The graph shows the distribution of the number of text messages young adults send per day. The distribution is approximately Normal, with a mean of 128 messages and a standard deviation of 30 messages.
A graph titled daily text messaging has number of text on the x-axis, going from 8 to 248 in increments of 30. Data is distributed normally. The highest point of the curve is at 128.
What percentage of young adults send between 68 and 158 text messages per day?
34%
47.5%
81.5%
95%
Answers
This value is approximate.
====================================================
Explanation:
We have a normal distribution with these parameters
mu = 128 = population meansigma = 30 = population standard deviationThe goal is to find the area under the curve from x = 68 to x = 158, where x is the number of text messages sent per day. So effectively, we want to find P(68 < x < 158).
Let's convert the score x = 68 to its corresponding z score
z = (x-mu)/sigma
z = (68-128)/30
z = -60/30
z = -2
This tells us that the score x = 68 is exactly two standard deviations below the mean mu = 128.
Repeat for x = 158
z = (x-mu)/sigma
z = (158-128)/30
z = 30/30
z = 1
This value is exactly one standard deviation above the mean
-------------------------------------------
The problem of finding P(68 < x < 158) can be rephrased into P(-2 < z < 1)
We do this because we can then use the Empirical rule as shown in the diagram below.
We'll focus on the regions between z = -2 and z = 1. This consists of the blue 13.5% on the left, and the two pink 34% portions. So we will say 13.5% + 34% + 34% = 81.5%
Approximately 81.5% of the the population sends between 68 and 158 text messages per day. This value is approximate because the percentages listed in the Empirical rule below are approximate.
Answer:
C. 81.5%
Step-by-step explanation:
Related Questions
Can someone please help me with this
Answers
9514 1404 393
Answer:
21. D
22. C
Step-by-step explanation:
21. The expansion of the given expression is ...
[tex]\displaystyle -\frac{1}{2}\left(-\frac{3}{2}x+6x+1\right)-3x=\frac{3}{4}x-3x-\frac{1}{2}-3x\\\\=\left(\frac{3}{4}-3-3\right)x-\frac{1}{2}=\boxed{-5\frac{1}{4}x-\frac{1}{2}}[/tex]
__
22. The least likely team to make the championship game is the one with the lowest probability.
3/8 < 1/2 < 2/3 < 4/5
The Bulldogs are least likely to play in the championship game.
find the value of the trigonometric ratio. make sure to simplify the fraction if needed
Answers
Answer:
Sin A = o/h
= 9/41
Step-by-step explanation:
since Sin is equal to opposite over hypotenuse, from the question, the opposite angle of A is 9 and hypotenuse angle of A is 41. Thus the answer for Sin A= 9/41
A contractor is purchasing some stone tiles for a new patio. Each cost $3 and he wants to spend less than $1200. The size of each tile is 1 square foot. Write an inequality that represents the number of tiles he can purchase with a $1200 limit, and then figure out how large the stone patio can be.
Answers
Answer:
4 0 0 s q. ft.Step-by-step explanation:
3x≤1200; 400 sq. ft.The lin 2x - 3y = 4 does not passes through the point :
A) (1/2,-1)
B) (2,0)
C) (1, -2/3)
D) (2,-1)
I would really appreciate it if some helps me with this question!
Answers
Answer:
The choose D (2, –1)
2x-3y=4 —> 3y=2X-4 —> y= 2/3x – 4/3
y=mx+b —> So ; m= 2/3 , b= - 4/3
y-intercept :(0, -4/3)
0=2/3x –4/3 —> 2/3x = 4/3 —> X=2
x-intercept ; (2,0)
By drawing a straight line from point 2 on the x-axis and point -4/3 on the y-axis, the points that are on the axis have been extracted, but the point (2,-1) is not on the axis . :)
I hope it helped you ^_^
Your credit card has a balance of $3300 and an annual interest rate of 14%. You decided to pay off the balance over two years. If there are no further purchases charged to the card, you must pay $158.40 each month, and you will pay a total interest of $501.60. Assume you decided to pay off the balance over one year rather than two. How much more must you pay each month and how much less will you pay in total interest?
Answers
9514 1404 393
Answer:
$137.90 more each month$246.00 less total interestStep-by-step explanation:
The amortization formula is ...
A = P(r/12)/(1 -(1 +r/12)^(-12t))
for the monthly payment on principal P at annual rate r for t years. Here, we have P=3300, r = 0.14, and t=1, so the monthly payment is ...
A = $3300(0.14/12)/(1 -(1 +0.14/12)^-12) ≈ $296.30
The payment of $296.30 is ...
$295.30 -158.40 = $137.90 . . . more each month
The total amount paid is 12×$296.30 = $3555.60, so 255.60 in interest. This amount is ...
$501.60 -255.60 = $246.00 . . . less total interest
Find the length of the other two sides isosceles right triangle
Answers
Answer:
x=5 and h=5*sqrt(2)
Step-by-step explanation:
It's an isosceles right triangle, x=5. Use Pythagoras and compute h
Instructions: Find the measure of the indicated angle to the nearest degree.
Answers
Answer:
? = 13.6
Step-by-step explanation:
Let the unknown angle be y
so
tan y= p/b
tan y =8/33
y = tan‐¹(8/33)
y = 13.62699486
y = 13.6
An airline charges the following baggage fees: $20 for the first bag and $40 for the second. Suppose 54% of passengers have no checked luggage, 25% have only one piece of checked luggage and 21% have two pieces. We suppose a negligible portion of people check more than two bags.
a) The average baggage-related revenue per passenger is: $___.
b) The standard deviation of baggage-related revenue is: $____.
c) About how much revenue should the airline expect for a flight of 120 passengers?
Answers
A distribution of values is normal with a mean of 60 and a standard deviation of 16. From this distribution, you are drawing samples of size 25. Find the interval containing the middle-most 76% of sample means.
Answers
Answer:
The interval containing the middle-most 76% of sample means is between 56.24 and 63.76.
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
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.
A distribution of values is normal with a mean of 60 and a standard deviation of 16.
This means that [tex]\mu = 60, \sigma = 16[/tex]
Samples of size 25:
This means that [tex]n = 25, s = \frac{16}{\sqrt{25}} = 3.2[/tex]
Find the interval containing the middle-most 76% of sample means.
Between the 50 - (76/2) = 12th percentile and the 50 + (76/2) = 88th percentile.
12th percentile:
X when Z has a p-value of 0.12, so X when Z = -1.175.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]-1.175 = \frac{X - 60}{3.2}[/tex]
[tex]X - 60 = -1.175*3.2[/tex]
[tex]X = 56.24[/tex]
88th percentile:
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]1.175 = \frac{X - 60}{3.2}[/tex]
[tex]X - 60 = 1.175*3.2[/tex]
[tex]X = 63.76[/tex]
The interval containing the middle-most 76% of sample means is between 56.24 and 63.76.
For this problem I thought the answer would be 1.3 for part C since it said to find the mean. However, I am wrong. Can someone help me with the problem please? Thank you for your help!
Answers
Answer:
Step-by-step explanation:
the mean is
{(12x1)+(13x1)+(14x2)+(15x2)+(17)+(18)+(19x2)+(20)+(21x2)+(22)+(24)}/11
mean=264/11
mean=24
An 8 sided die, which may or may not be a fair die, has 4 colors on it; you have been tossing the die for an hour and have recorded the color rolled for each loss. What is the probability you will roll a purple on your next toss of the die? Enter your answer as a simplified fraction or a decimal rounded to four decimal places.
Red Purple Yellow Orange
44 37 41 21
Answers
Answer:
0.2587 = 25.87% probability you will roll a purple on your next toss of the die.
Step-by-step explanation:
A probability is the number of desired outcomes divided by the number of total outcomes.
In an experimental probability, which is the case in this question, the number of outcomes is taken from previous experiments.
In this question:
44 + 37 + 41 + 21 = 143 tosses.
37 purple.
What is the probability you will roll a purple on your next toss of the die?
[tex]p = \frac{37}{143} = 0.2587[/tex]
0.2587 = 25.87% probability you will roll a purple on your next toss of the die.
Interpret the coefficient of determination. Choose the correct answer below. A. The coefficient of determination measures the percent of variation not explained by the multiple regression model. B. The coefficient of determination measures the percent of variation explained by the multiple regression model. C. The coefficient of determination measures the expected error of the predicted sales given a specific total square footage and number of shopping centers. D. The coefficient of determination measures the average predicted sales for the multiple regression model.
Answers
Answer:
B.The coefficient of determination measures the percent of variation explained by the multiple regression model.
Step-by-step explanation:
The answer to this question is option b because the coefficient of variation R² gives a measure of the variability that is ending y values or the dependent variables which can be explained in a multiple linear regression.
In simpler words, it is the percentage of proportion of variation in the dependent variable that can be predicted using the explanatory variables.
find the exact value of tan(165°) using a difference of two angles
Answers
Answer: [tex]-2+\sqrt{3}[/tex]
=========================================================
Work Shown:
Apply the following trig identity
[tex]\tan(A - B) = \frac{\tan(A)-\tan(B)}{1+\tan(A)*\tan(B)}\\\\\tan(225 - 60) = \frac{\tan(225)-\tan(60)}{1+\tan(225)*\tan(60)}\\\\\tan(165) = \frac{1-\sqrt{3}}{1+1*\sqrt{3}}\\\\\tan(165) = \frac{1-\sqrt{3}}{1+\sqrt{3}}\\\\[/tex]
Now let's rationalize the denominator
[tex]\tan(165) = \frac{1-\sqrt{3}}{1+\sqrt{3}}\\\\\tan(165) = \frac{(1-\sqrt{3})(1-\sqrt{3})}{(1+\sqrt{3})(1-\sqrt{3})}\\\\\tan(165) = \frac{(1-\sqrt{3})^2}{(1)^2-(\sqrt{3})^2}\\\\\tan(165) = \frac{(1)^2-2*1*\sqrt{3}+(\sqrt{3})^2}{(1)^2-(\sqrt{3})^2}\\\\\tan(165) = \frac{1-2\sqrt{3}+3}{1-3}\\\\\tan(165) = \frac{4-2\sqrt{3}}{-2}\\\\\tan(165) = -2+\sqrt{3}\\\\[/tex]
----------------------
As confirmation, you can use the idea that if x = y, then x-y = 0. We'll have x = tan(165) and y = -2+sqrt(3). When computing x-y, your calculator should get fairly close to 0, if not get 0 itself.
Or you can note how
[tex]\tan(165) \approx -0.267949\\\\-2+\sqrt{3} \approx -0.267949[/tex]
which helps us see that they are the same thing.
Further confirmation comes from WolframAlpha (see attached image). They decided to write the answer as [tex]\sqrt{3}-2[/tex] but it's the same as above.
6. The perimeter of a square room is 48 m, how much square metre carpet required it cover it ?
Answers
Answer:
144
Step-by-step explanation:
Answer:
first you have to now each side length ,since it is square so all sides are equal so 48/4=12 i.e perimeter =4 so our qoustion is area so the area of square is side square
Step-by-step explanation:
so side =12 , 12square is 144 that set.
Use the point-slope form from the previous question and fill-in the following table of values.
The point-slope equation went through the following 2 points: (0, -1) and (1, 2)
(0, -1)
(1, 2)
(2, )
(3, )
Answers
Answer:
Step-by-step explanation:
Slope of line through (0,-1) and (1,2) = (-1 - 2)/(0 - 1) = 3
Point-slope equation for line of slope 3 that passes through (0,-1):
y+1 = 3(x-0)
When x = 2:
y+1 = 3(2-0)
y = 3·2 - 1 = 5
When x = 3:
y+1 = 3(3-0)
y = 3·3-1 = 8
Help ASAP please !!
Answers
Option 4
Answered by Gauthmath must click thanks and mark brainliest
Find m<1.
33°
47°
42°
28°
Answers
Answer:
<1 = 33
Step-by-step explanation:
The sum of the angle of a triangle is 180
31+116+x = 180
x+147=180
x = 180-147
x = 33
What is a placement form from the school mean
Answers
Answer:
Placements are basically extended internships or work experience assignments
Step-by-step explanation:
What is the x-intercept of the graph of the function f(x) = x2 − 16x + 64?
(−8, 0)
(0, 8)
(8, 0)
(0, −8)
Answers
Answer:
(8,0)
Step-by-step explanation:
f(x) = x^2 − 16x + 64
The x intercepts ( or zeros) are found by setting y=0
0 = x^2 − 16x + 64
Factor
0 = (x-8)(x-8)
Using the zero product property
x-8 =0 x-8 =0
x=8 x=8
(8,0)
Answer:
8,0
edge 20201
need help asap :) ty
Answers
Answer:
3:7
Step-by-step explanation:
i hope this helps
find the volume of each figure. Round to the nearest tenth if necessary.
Answers
Volume of Triangular Prism = 1/2(bhl)
Base = 8
Height = 6
Length = 11
Volume = 1/2(8×6×11)
= 264yd³
Must click thanks and mark brainliest
This graph shows a portion of an odd function.
Use the graph to complete the table of values.
X
f(x)
-2.
-3
-4
-6
DONE
Answers
9514 1404 393
Answer:
-2-1-2-3Step-by-step explanation:
An odd function is symmetrical about the origin:
f(-x) = -f(x)
So, ...
f(-2) = -f(2) = -2
f(-3) = -f(3) = -1
f(-4) = -f(4) = -2
f(-6) = -f(6) = -3
Answer:
-2
-1
-2
-3
I did it on edge2020 and got it right
धरोहर को वाक्य बनाऊ
Answers
Answer:
Please tell in english
Step-by-step explanation:
Mrs. Gomez has two kinds of flowers in her garden. The ratio of lilies to daisies in the garden is 5:2
If there are 20 lilies, what is the total number of flowers in her garden?
Answers
Answer:
28
Step-by-step explanation:
5 : 2
since this is a simplified ratio, they have a common factor. let's say it is 'x'
so now :
5x : 2x
we know that 5x is lilies, and we also know that she has 20 lilies, so:
5x = 20
x = 4
the daisies would be 2x so 2*4 = 8
total flowers is 20 + 8
28
Please help explanation need it
Answers
Answer:
[tex] \cos(z) = \frac{30}{34} [/tex]
After conducting a survey of all her classmates, Midge discovers that the amount of money everyone spends buying books each month has a mean of $30. What does the mean say about the amount her classmates spend on books?
Half of her classmates spend exactly $30 per month buying books.
Half of her classmates spend more than $30 per month buying books.
The majority of her classmates spend $30 per month buying books.
If the amount spent on books per month by all her the classmates is leveled, that amount would be $30.
Answers
Answer:
If the amount spent on books per month by all her the classmates is leveled, that amount would be $30.
Step-by-step explanation:
The mean is the average amount calculated by finding the sum of a certain group of numbers, then dividing it.
This can be described as "leveling" the amount, since it is the total average.
So, the mean of $30 in this situation means that the average amount that her classmates spend on books is $30.
The correct answer is that If the amount spent on books per month by all her the classmates is leveled, that amount would be $30.
Answer:
Your answer is D
Step-by-step explanation:
Please give top guy brainiest
Solve the following system of equations and show all your work y=2x^2 y=3x-1
Answers
Answer:
( 1/2 ; 1/2 ) and ( 1 ; 2 )
Step-by-step explanation:
y = 2x².............1
y = 3x-1............2
2x²=3x-1
2x²-3x+1 = 0
(2x-1)(x-1) = 0
x = 1/2 or x = 1
y = 1/2 or y = 2
Let f(x)=5-4x. Find f(3)
Answers
Answer:
-7
Step-by-step explanation:
f(x) = 5 - 4x
f(3) = 5 - 4(3) (since x = 3)
f(3) = 5 - 12
f(3) = -7
PLS ANSWER FAST!!! IM GONNA FAIL!!!
Mike and his friends bought cheese wafers for $2 per packet and chocolate wafers for $1 per packet at a carnival. They spent a total of $25 to buy a total of 20 packets of wafers of the two varieties.
Part A: Write a system of equations that can be solved to find the number of packets of cheese wafers and the number of packets of chocolate wafers that Mike and his friends bought at the carnival. Define the variables used in the equations. (5 points)
Part B: How many packets of chocolate wafers and cheese wafers did they buy? Explain how you got the answer and why you selected a particular method to get the answer. (5 points)
Answers
Step-by-step explanation:
p-cheese wafers
q-chocolate wafers
p2 + q1 = $25
5(2) + 15(1) = $25
Just used numbers that added up to 20 starting from 2 going up
When f(x) =-3 what is x?
Answers
Answer:
D or -1
Step-by-step explanation:
It says that f(x) is equal to -3.
f(x) is the same as y-values, and x is the same as the x-values on a coordinate grid because x is the independent variable, meaning y is the dependent variable, where f(x) depends on the value of x to find y.
So if y is -3, it can be found on the graph on the 4th line, so x = -1 when y = -3
