Answers
Answer:
See below
Step-by-step explanation:
a)
[tex]2\sin(x) +\sqrt{3} =0 \implies 2\sin(x)=-\sqrt{3} \implies \boxed{\sin(x)=-\dfrac{\sqrt{3}}{2} }[/tex]
[tex]\therefore x=\dfrac{4\pi }{3}[/tex]
But note, as sine does represent the [tex]y[/tex] value, [tex]\dfrac{5\pi }{3}[/tex] is also solution
Therefore,
[tex]x=\dfrac{4\pi }{3} \text{ and } x=\dfrac{5\pi }{3}[/tex]
This is the solution for [tex]x\in[0, 2\pi ][/tex], recall the unit circle.
Note: [tex]\sin(x)=-\dfrac{\sqrt{3}}{2} \implies \sin(x)=\sin \left(\pi +\dfrac{\pi }{3} \right)[/tex]
b)
[tex]\sqrt{3} \tan(x) + 1 =0 \implies \tan(x) = -\dfrac{1}{\sqrt{3} } \implies \boxed{ \tan(x) = -\dfrac{\sqrt{3} }{3} }[/tex]
Once
[tex]\tan(x) = -\dfrac{\sqrt{3} }{3} \implies \sin(x) = -\dfrac{1}{2} \text{ and } \cos(x) = \dfrac{\sqrt{3} }{2}[/tex]
As [tex]\tan(x) = \dfrac{\sin(x)}{\cos(x)}[/tex]
[tex]\therefore x=-\dfrac{\pi }{6}[/tex]
c)
[tex]4\sin^2(x) - 1 = 0 \implies \sin^2(x) = \dfrac{1}{4} \implies \boxed{\sin(x) = \pm \dfrac{\sqrt{1} }{\sqrt{4} } = \pm \dfrac{1}{2}}[/tex]
Therefore,
[tex]\sin(x)=\dfrac{1}{2} \implies x=\dfrac{\pi }{6} \text{ and } x=\dfrac{5\pi }{6}[/tex]
[tex]\sin(x)=-\dfrac{1}{2} \implies x=\dfrac{7\pi }{6} \text{ and } x=\dfrac{11\pi }{6}[/tex]
The solutions are
[tex]x=\dfrac{\pi }{6} \text{ and } x=\dfrac{5\pi }{6} \text{ and }x=\dfrac{7\pi }{6} \text{ and } x=\dfrac{11\pi }{6}[/tex]
Related Questions
Working for a car company, you have been assigned to find the average miles per gallon (mpg) for acertain model of car. you take a random sample of 15 cars of the assigned model. based on previous evidence and a qq plot, you have reason to believe that the gas mileage is normally distributed. you find that the sample average miles per gallon is around 26.7 with a standard deviation of 6.2 mpg.
a. Construct and interpret a 95% condence interval for the mean mpg, , for the certain model of car.
b. What would happen to the interval if you increased the condence level from 95% to 99%? Explain
c. The lead engineer is not happy with the interval you contructed and would like to keep the width of the whole interval to be less than 4 mpg wide. How many cars would you have to sample to create the interval the engineer is requesting?
Answers
Answer:
a) The 95% confidence interval for the mean mpg, for the certain model of car is (23.3, 30.1). This means that we are 95% sure that the true mean mpg of the model of the car is between 23.3 mpg and 30.1 mpg.
b) Increasing the confidence level, the value of T would increase, thus increasing the margin of error and making the interval wider.
c) 37 cars would have to be sampled.
Step-by-step explanation:
Question a:
We have the sample standard deviation, and thus, the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 15 - 1 = 14
95% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 14 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 2.1448
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 2.1448\frac{6.2}{\sqrt{15}} = 3.4[/tex]
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 26.7 - 3.4 = 23.3 mpg.
The upper end of the interval is the sample mean added to M. So it is 26.7 + 3.4 = 30.1 mpg.
The 95% confidence interval for the mean mpg, for the certain model of car is (23.3, 30.1). This means that we are 95% sure that the true mean mpg of the model of the car is between 23.3 mpg and 30.1 mpg.
b. What would happen to the interval if you increased the confidence level from 95% to 99%? Explain
Increasing the confidence level, the value of T would increase, thus increasing the margin of error and making the interval wider.
c. The lead engineer is not happy with the interval you constructed and would like to keep the width of the whole interval to be less than 4 mpg wide. How many cars would you have to sample to create the interval the engineer is requesting?
Width is twice the margin of error, so a margin of error of 2 would be need. To solve this, we have to consider the population standard deviation as [tex]\sigma = 6.2[/tex], and then use the z-distribution.
We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:
[tex]\alpha = \frac{1 - 0.95}{2} = 0.025[/tex]
Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].
That is z with a pvalue of [tex]1 - 0.025 = 0.975[/tex], so Z = 1.96.
Now, find the margin of error M as such
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.
How many cars would you have to sample to create the interval the engineer is requesting?
This is n for which M = 2. So
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
[tex]2 = 1.96\frac{6.2}{\sqrt{n}}[/tex]
[tex]2\sqrt{n} = 1.96*6.2[/tex]
[tex]\sqrt{n} = \frac{1.96*6.2}{2}[/tex]
[tex](\sqrt{n})^2 = (\frac{1.96*6.2}{2})^2[/tex]
[tex]n = 36.9[/tex]
Rounding up:
37 cars would have to be sampled.
if you can type 55 words in 20 seconds how much can you type in 1007 seconds
Answers
Answer:
[tex]55385[/tex]
words
Step-by-step explanation:
because
I) we have given 55 words
ii) we have given a time 20 seconds
iii) then we multiple 55 ×1007
iv) the answer will be 55385
Insurance companies are interested in knowing the population percentage of drivers who always buckle up before riding in a car. When designing a study to determine this population proportion, what is the minimum number of drivers you would need to survey to be 95% confident that the population proportion is estimated to within 0.04
Answers
Answer:
The minimum number of drivers you would need to survey is 601.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
The margin of error is:
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
95% confidence level
So [tex]\alpha = 0.05[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].
What is the minimum number of drivers you would need to survey to be 95% confident that the population proportion is estimated to within 0.04?
The number is n for which M = 0.04.
We don't have an estimate for the proportion, so we use [tex]\pi = 0.5[/tex]. Then
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
[tex]0.04 = 1.96\sqrt{\frac{0.5*0.5}{n}}[/tex]
[tex]0.04\sqrt{n} = 1.96*0.5[/tex]
[tex]\sqrt{n} = \frac{1.96*0.5}{0.04}[/tex]
[tex](\sqrt{n})^2 = (\frac{1.96*0.5}{0.04})^2[/tex]
[tex]n = 600.25[/tex]
Rounding up:
The minimum number of drivers you would need to survey is 601.
Hey community I thank you guys fir your help
Answers
Answer:
A, B, and E.
Step-by-step explanation:
A. 5^x * 5^x
= 5^x+x
=5^(2)(x)
=25^x
B. 5^2x
=5^(2)(x)
=25^x
C. 5*5^2x
=5^1+2x
D. 5*5^x
=5^1+x
E. (5*5)^x
=5^x*5^x
=5^(2)(x)
=25^x
F. 5^2*5^x
=5^2+x
Which equation represents the data in
the table?
x 0 1 2 3 4
y -4 -2 0 2 4
F y= x -4
G y= 2x -2
H y = 2x - 4
I y= 4x -4
Answers
Answer:
y = 2x - 4
Step-by-step explanation:
The equations are put in slope intercept form
Slope intercept form: y = mx + b
Where m = slope and b = y intersect
So in order to find the equation of the data represented by the table we will have to find the slope and y intercept
Let's begin!
First let's find the slope
We can find the slope by using the slope formula
m = (y2 - y1) / (x2 - x1) where the x and y values are derived from coordinates from the table
The points chosen may vary but I have chosen the points (0,-4) and (1,-2)
Now that we have chosen the points we will use to find the slope let's define the variables
remember coordinates are written like this: (x,y)
The x value of the second coordinate is 1 so x2 = 1
The x value of the first coordinate is 0
So x1 = 0
The y value of the second coordinate is -2 so y2 = -2
The y value of the first coordinate is -4
So y1 = -4
Now that we have defined each variable let's plug in the values into the formula
Formula: m = (y2 - y1) / (x2 - x1)
Variables: x2 = 1, x1 = 0, y2 = -2, y1 = -4
Substitute values
m = (-2 - (-4) / ( 1 - 0 )
Evaluate
The negative signs cancel out on top and it changes to +4
m = (-2 + 4)/(1-0)
Add top values
m = 2/(1-0)
Subtract bottom numbers
m = 2/1
Simplify fraction
m = 2
So we can conclude that the slope (m) = 2
Now let's find the y intercept or "b"
The y intercept is the value of y when x = 0
If you look at the table when x = 0 y = -4 meaning that the y intercept or "b" is -4
Now that we have found everything let's find the equation of the data represented by the table
The equation is in slope intercept form
y = mx + b
Define variables
m = 2 and b = -4
Substitute values
y = 2x - 4
The equation is y = 2x - 4
i need help asap !!!
Answers
I need to solve for x and z if you could explain as well. Thank you
Answers
Answer:
x = 6
z = 60
Step-by-step explanation:
Solve for x
(6x + 84) = 120
- 84 -84
6x = 36
6x/6 = 36/6
x = 6
Then solve for z
120 + z = 180
-120 -120
z = 60
Can someone help me? I figured out part B however, I am struggling with part A and I would be so happy if any of you helped me. Thank you for your help.
Answers
Note: you may need to delete the comma
============================================================
Explanation:
The info "5 months" is never used to compute the mean. We could easily replace it with "6 months" or "7 months" or any stretch of time, and still get the same answer. So we'll ignore this value.
What we'll do is add up the 21 items given to us, and then divide by 21.
Because there are so many values, and it's easy to get lost, I'm going to add up across the rows
Row One: 256,229+253,657+218,747+246,163+235,626+288,694 = 1,499,116 Row Two: 316,265+196,721+319,620+285,077+215,152+253,291 = 1,586,126 Row Three: 315,011+199,901+265,443+291,806+303,556+215,359 = 159,1076 Row Four: 258,554+293,658+289,935 = 842,147Those subtotals then add up to this
1,499,116+1,586,126+1,591,076+842,147 = 5,518,465
This is the same as adding up all 21 values.
Finally, we divide that sum over 21 as there are 21 values in this list
(5,518,465)/21 = 262,784.047619048
That value then rounds up to 262,785
If your teacher just wanted things to the nearest whole number (without rounding up), then the answer would be 262,784
Side note: using a spreadsheet program would probably be the most efficient/fastest method for this type of problem.
You are skiing down a mountain with a vertical height of 1250 feet. The distance that you ski as you go from the top down to the base of the mountain is 3350 feet. Find the angle of elevation from the base to the tep of the mountain. Round your answer to a whole number as necessary.
Answers
Step-by-step explanation:
here is the answer to your question
A garden table and a bench cost $717 combined. The garden table costs $67 more than the bench. What is the cost of the bench?
Answers
Subtract the difference form the total:
717 - 67 = 650
Divide the remaining amount by 2:
650/2 = 375
The bench cost$375
please give me correct answer
Answers
Answer:
36 = 17+19 ---> They are twin primes and their sum is 3684 = 41+43 ---> They are twin Primes and sum is 84120 = 59+61 ---> They also are twin primes and their sum is 120144 = 71+73 ---> They are also twin primes and the sum is 144the tangent of theta is 1, the terminal side of theta lies in the 3rd quadrant. what is a possible value for theta? give your answer in radians or degrees
Answers
Answer:
5π/4 radians or 225°
Step-by-step explanation:
please help me with this
Answers
Given:
d = 2
f = 4
To find:
Value of [tex]\frac{14(7)-d}{2f}[/tex]
Steps:
we need to substitute and then find the value,
[tex]= \frac{14(7)-2}{2(4)}\\ \\=\frac{98-2}{8} \\\\=\frac{96}{8}\\\\=12[/tex]
Therefore, the answer is option C) 12
Happy to help :)
If you need help, feel free to ask
A value meal package at Ron's Subs consists of a drink, a sandwich, and a bag of chips. There are 66 types of drinks to choose from, 33 types of sandwiches, and 44 types of chips. How many different value meal packages are possible
Answers
36 different value meal packages are possible
Step-by-step explanation:
To answer this question, multiply all given numbers together.
4*3*3
12*3
36
HELP PLEASE!!!!
The median age for a first marriage in the United States for women was 25.9 in 2009 and 26.1 in 2010. Use an exponential model to predict the median age for women in 2019, where x is the number of years since 2009.
A) 23.9
B) 28.3
C) 28.0
D) 24.0
Answers
Answer:
29.1 Is the answer for 2009
Step-by-step explanation:
How many solutions on the interval {0, 2020} sin 2x + 1 + sin x + cos x have?
Answers
Answer:
0
Step-by-step explanation:
PLS HELP
Let f(x) = -2x - 7 and g(x) = -4x + 6. Find (g o f) (-5)
–6
3
–59
26
Answers
Answer:
-6
Step-by-step explanation:
f(x) = -2x - 7 and g(x) = -4x + 6
Find f(-5)
f(-5) = -2(-5) -7 = 10-7 = 3
The find g(3)
g(3) = -4(3) +6
= -12 +6 =-6
g(f(-5)) = -6
pls help me with this. You need to graph the equation or smt
Answers
have a good day
pls help
Drag each tile to the correct location on the inequality. Each tile can be used more than once.
Consider the graphed function.
y2
8
-6
H4
+2
-6
-4
-2
2
4
6
8
-2
-6
8
What are the domain and the range of this function?
-5
2021 Edmentum. All rights reserved.
Answers
The given graph is a line and he line is the distance between two points. The required equation of the line is y = 0.5x + 5
Inequality graphThe given graph is a line and he line is the distance between two points. The equation of a line is represented as;
y = mx+ b
m is the slopeb is the interceptGiven the coordinate points (-5, 4) and (1, 7)
Get the slope
Slope = 7-4/1-(-5)
Slope = 3/6
Slope = 0.5
The intercept is 5 (the point where the line cuts the y-axis)
Determine the required equation
y = 0.5x + 5
Hence the required equation of the line is y = 0.5x + 5
Learn more on line here: https://brainly.com/question/18831322
#SPJ1
One card is randomly selected from a deck of cards. Find the odds against drawing a black 10.
The odds against drawing a black ten are ___:___.
(Simplify your answers.)
Answers
Answer:
25/26 or 26/27 depending on free hands.
The first is if you don't use jokers/free cards
There is 13 cards in a single set, and a single 10 card.
Two sets are black and two sets a red.
Hearts, Spades, Clubs, and Diamonds
There is only 2 black tens out of 52 or 54 cards, so we can set it up as
50/52 or 52/54 which is simplified to
25/26 or 26/27 depending on free hands.
Step-by-step explanation:
Which of the following behaviors would best describe someone who is listening and paying attention? a) Leaning toward the speaker O b) Interrupting the speaker to share their opinion c) Avoiding eye contact d) Asking questions to make sure they understand what's being said
Answers
Answer:
D
Step-by-step explanation:
I explained why 5 minutes ago on a different question
what is 5 2/3 - 11 1/6
Answers
Answer:
Check the photo for the answer
SOMEONE PLS HELP!!!!
Determine if the function f is an exponential function. If so, identify the base. If not, why not? f(x) = 3x + 1
A) This is a polynomial.
B) The base is x + 1.
C) The base is 3.
D) This is not an exponential function because the variable is in the exponent position.
Answers
Answer:
Step-by-step explanation:
Is the function f(x) = 3x+1, f(x) = 3ˣ⁺¹, or f(x) = 3ˣ+1 ?
f(x) = 3x+1 is not an exponential function. It is a straight line.
f(x) = 3ˣ⁺¹ Is an exponential function. The base is 3.
f(x) = 3ˣ+1 is an exponential function. The base is 3.
Solve the following equation for x. 12^2 - 36x = 0
Answers
For a 13-person team, how does the actual weekly labor cost compare to the targeted labor cost?
Answers
The actual labor cost is $600 over the targeted labor cost.
Given that,
Work done by each person per week = 40 hours
Required labor hours per week = 600 hours
No. of workers in the team = 13
To find,
Actual weekly labor cost = ?
Procedure:
Actual weekly labor cost = No. of workers * no. of hours performed by them
[tex]= 13 * 40[/tex]
[tex]= 520 hours[/tex]
Given that,
[tex]Regular rate = $ 15.00 per hour[/tex]
[tex]Overtime rate = $ 22.50 per hour[/tex]
Thus,
Actual labor cost = (regular hours worked * regular rate) + (overtime * overtime rate)
[tex]= (520 * 15) + ([600 - 520] * 22.50)[/tex]
[tex]= $ 7,800 + $ 1,800[/tex]
[tex]= $ 9600[/tex]
Targeted Labor cost = $ 9,000 per week
Thus, option C i.e. the actual labor cost is $ 600 over the targeted labor cost.
Learn more about 'Labor Cost' here:
brainly.com/question/5427701
The triangles are similar. Find x.
Please help me!
Answers
GIVEN -> Triangles r similar
so sides r in ratio
[tex] \frac{2.4}{3} = \frac{2.8}{x} \\ 0.8 = \frac{2.8}{x} \\ x = \frac{2.8}{0.8} \\ x = \frac{28}{8} \\ x = 3.5 \: \: ans[/tex]
Answer:
3.5
Step-by-step explanation:
We can write a ratio to solve
2.4 2.8
----- = --------
3 x
Using cross products
2.4x = 3(2.8)
2.4x =8.4
Divide each side by 2.4
2.4x /2.4 = 8.4/2.4
x = 3.5
X,and z are midpoints.find the length of each segment
Answers
Answers:
MZ = 10ZO = 10MO = 20XZ = 9YZ = 7===========================================
Explanation:
Side MO is twice as long as the midsegment XY. Note how XY and MO are parallel.
This makes
MO = 2*XY = 2*10 = 20
Side MO breaks into two equal halves MZ and ZO
Each of MZ and ZO are 20/2 = 10 units long.
Put another way: XY, MZ and ZO are all the same length (all 10 units long).
---------------
The diagram shows that segment NO is 18 units long, which cuts in half to 18/2 = 9. This is the length of NY, YO and XZ
Also, MN = 14 which cuts in half to 7. This means MX, XN and YZ are all 7 units each.
Calculate the GPA of a student with the following grades: B (77 hours), D (66 hours), F (2020 hours). Note that an A is equivalent to 4.04.0, a B is equivalent to a 3.03.0, a C is equivalent to a 2.02.0, a D is equivalent to a 1.01.0, and an F is equivalent to a 00. Round your answer to two decimal places.
Answers
Answer:
The student's GPA is of 0.82.
Step-by-step explanation:
GPA:
To find the student's GPA, we find his weighed mean.
Grades:
7 hours worth 3(B)
6 hours worth 1(D)
20 hours worth 0(F). So
[tex]M = \frac{7*3 + 6*1 + 20*0}{7+6+20} = 0.82[/tex]
The student's GPA is of 0.82.
Given ADEF: ARST, find the scale factor
Answers
Answer:
the scale factor is 3/4
x = 16×3/4 = 12
Step-by-step explanation:
the only side length we have for both triangles is the short left side.
we see that we get ED from SR and need to transform 4 into 3. how do we do that ?
well,
4×f = 3
f = 3/4
that is the scaling factor, as all side lengths in EDF are created by multiplying the corresponding side in SRT by the same scaling factor (3/4).
therefore,
x = EF = ST×f = 16×3/4 = 4×3 = 12
Answer:
The scale factor is 4/3 and x is 12
Step-by-step explanation:
→ Divide RS by DE
4 ÷ 3 = 4/3
→ Divide the answer by 16
16 ÷ 4/3 = 12
A sample of 42 observations is selected from one population with a population standard deviation of 3.3. The sample mean is 101.0. A sample of 53 observations is selected from a second population with a population standard deviation of 3.6. The sample mean is 99.0. Conduct the following test of hypothesis using the 0.04 significance level.
H0 : μ1 = μ2
H1 : μ1 ≠ μ2
a. State the decision rule.
b. Compute the value of the test statistic.
c. What is your decision regarding H0?
d. What is the p-value?
Answers
Answer:
a)
[tex]|z| < 2.054[/tex]: Do not reject the null hypothesis.
[tex]|z| > 2.054[/tex]: Reject the null hypothesis.
b) [tex]z = 2.81[/tex]
c) Reject.
d) The p-value is 0.005.
Step-by-step explanation:
Before testing the hypothesis, we need to understand the central limit theorem and the subtraction of normal variables.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
Population 1:
Sample of 42, standard deviation of 3.3, mean of 101, so:
[tex]\mu_1 = 101[/tex]
[tex]s_1 = \frac{3.3}{\sqrt{42}} = 0.51[/tex]
Population 2:
Sample of 53, standard deviation of 3.6, mean of 99, so:
[tex]\mu_2 = 99[/tex]
[tex]s_2 = \frac{3.6}{\sqrt{53}} = 0.495[/tex]
H0 : μ1 = μ2
Can also be written as:
[tex]H_0: \mu_1 - \mu_2 = 0[/tex]
H1 : μ1 ≠ μ2
Can also be written as:
[tex]H_1: \mu_1 - \mu_2 \neq 0[/tex]
The test statistic is:
[tex]z = \frac{X - \mu}{s}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, and s is the standard error .
a. State the decision rule.
0.04 significance level.
Two-tailed test(test if the means are different), so between the 0 + (4/2) = 2nd and the 100 - (4/2) = 98th percentile of the z-distribution, and looking at the z-table, we get that:
[tex]|z| < 2.054[/tex]: Do not reject the null hypothesis.
[tex]|z| > 2.054[/tex]: Reject the null hypothesis.
b. Compute the value of the test statistic.
0 is tested at the null hypothesis:
This means that [tex]\mu = 0[/tex]
From the samples:
[tex]X = \mu_1 - \mu_2 = 101 - 99 = 2[/tex]
[tex]s = \sqrt{s_1^2 + s_2^2} = \sqrt{0.51^2 + 0.495^2} = 0.71[/tex]
Value of the test statistic:
[tex]z = \frac{X - \mu}{s}[/tex]
[tex]z = \frac{2 - 0}{0.71}[/tex]
[tex]z = 2.81[/tex]
c. What is your decision regarding H0?
[tex]|z| = 2.81 > 2.054[/tex], which means that the decision is to reject the null hypothesis.
d. What is the p-value?
Probability that the means differ by at least 2, either plus or minus, which is P(|z| > 2.81), which is 2 multiplied by the p-value of z = -2.81.
Looking at the z-table, z = -2.81 has a p-value of 0.0025.
2*0.0025 = 0.005
The p-value is 0.005.
