Answer:
a) The error bound of the confidence interval is of 0.66.
b) The confidence interval will be narrower.
Step-by-step explanation:
Question a:
We have to find the margin of error. Considering that we have the standard deviation for the sample, the t-distribution is used.
The first step to solve this problem is finding how many degrees of freedom,which is the sample size subtracted by 1. So
df = 71 - 1 = 70
95% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 70 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 1.9944
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}}[/tex]
In which s is the standard deviation of the sample and n is the size of the sample.
For this problem, [tex]s = 2.8, n = 71[/tex]. So
[tex]M = T\frac{s}{\sqrt{n}} = 1.9944\frac{2.8}{\sqrt{71}} = 0.66[/tex]
The error bound of the confidence interval is of 0.66.
b. What will happen to the level of confidence obtained if 1,000 male Swedes are surveyed instead of 48? Why?
The margin of error is inversely proportional to the square root of the sample size, so increasing the sample size leads to a smaller margin of error and a narrower confidence interval.
The point (7, 8) is the solution of which of the following systems of equations?
1. 8x - y = 48
9x + 10y = 142
2. 9x - y = 55
8x + 10y = 140
3. x-6y=-41
8x + 9y = 127
4. x-7y=-49
10x + 9y = 142
Option 4
Verification:-
[tex]\\ \sf\longmapsto x-7y=-49[/tex]
[tex]\\ \sf\longmapsto 7-7(8)=-49[/tex]
[tex]\\ \sf\longmapsto 7-56=-49[/tex]
[tex]\\ \sf\longmapsto -49=-49[/tex]
And
[tex]\\ \sf\longmapsto 10x+9y=142[/tex]
[tex]\\ \sf\longmapsto 10(7)+9(8)=142[/tex]
[tex]\\ \sf\longmapsto 70+72=142[/tex]
[tex]\\ \sf\longmapsto 142+142[/tex]
Hence verified
Answer:
4.
Step-by-step explanation:
1. 8x - y = 48
9x + 10y = 142
8(7) - 8 = 48
9(7) + 10(8) = 143
No
2. 9x - y = 55
8x + 10y = 140
9(7) - 8 = 55
9(7) - 10(7) = -24
No
3. x-6y=-41
8x + 9y = 127
7 - 6(8) = -41
8(7) + 9(8) = 128
No
4. x-7y=-49
10x + 9y = 142
7 - 7(8) = 49
10(7) + 9(8) = 142
Yes
A company that produces DVD drives has a 12% defective rate. Let X represent the number of defectives in a random sample of 55 of their drives.
Required:
a. What is the probability the sample will contain exactly 8 defective drives?
b. What is the probability the sample will contain more than 8 defective drives?
c. What is the probability the sample will contain less than 8 defective drives?
d. What is the expected number of defective drives in the sample?
Answer:
a) 0.1287 = 12.87% probability the sample will contain exactly 8 defective drives
b) 0.2092 = 20.92% probability the sample will contain more than 8 defective drives.
c) 0.6621 = 66.21% probability the sample will contain less than 8 defective drives.
d) The expected number of defective drives in the sample is 6.6
Step-by-step explanation:
For each DVD, there are only two possible outcomes. Either it is defective, or it is not. The probability of a DVD being defective is independent of any other DVD, which means that the binomial probability distribution is used to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
And p is the probability of X happening.
A company that produces DVD drives has a 12% defective rate.
This means that [tex]p = 0.12[/tex]
Let X represent the number of defectives in a random sample of 55 of their drives.
This means that [tex]n = 55[/tex]
a. What is the probability the sample will contain exactly 8 defective drives?
This is [tex]P(X = 8)[/tex]. So
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 8) = C_{55,8}.(0.12)^{8}.(0.88)^{47} = 0.1287[/tex]
0.1287 = 12.87% probability the sample will contain exactly 8 defective drives.
b. What is the probability the sample will contain more than 8 defective drives?
This is:
[tex]P(X > 8) = 1 - P(X \leq 8)[/tex]
In which:
[tex]P(X \leq 8) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) + P(X = 6) + P(X = 7) + P(X = 8)[/tex]
Then
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{55,0}.(0.12)^{0}.(0.88)^{55} = 0.0009[/tex]
[tex]P(X = 1) = C_{55,1}.(0.12)^{1}.(0.88)^{54} = 0.0066[/tex]
[tex]P(X = 2) = C_{55,2}.(0.12)^{2}.(0.88)^{53} = 0.0244[/tex]
[tex]P(X = 3) = C_{55,3}.(0.12)^{3}.(0.88)^{52} = 0.0588[/tex]
[tex]P(X = 4) = C_{55,4}.(0.12)^{4}.(0.88)^{51} = 0.1043[/tex]
[tex]P(X = 5) = C_{55,5}.(0.12)^{5}.(0.88)^{50} = 0.1450[/tex]
[tex]P(X = 6) = C_{55,8}.(0.12)^{6}.(0.88)^{49} = 0.1648[/tex]
[tex]P(X = 7) = C_{55,7}.(0.12)^{7}.(0.88)^{48} = 0.1573[/tex]
[tex]P(X = 8) = C_{55,8}.(0.12)^{8}.(0.88)^{47} = 0.1287[/tex]
So
[tex]P(X \leq 8) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) + P(X = 6) + P(X = 7) + P(X = 8) = 0.0009 + 0.0066 + 0.0244 + 0.0588 + 0.1043 + 0.1450 + 0.1648 + 0.1573 + 0.1287 = 0.7908[/tex]
[tex]P(X > 8) = 1 - P(X \leq 8) = 1 - 0.7908 = 0.2092[/tex]
0.2092 = 20.92% probability the sample will contain more than 8 defective drives.
c. What is the probability the sample will contain less than 8 defective drives?
This is:
[tex]P(X < 8) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) + P(X = 6) + P(X = 7)[/tex]
With the values we found in b.
[tex]P(X < 8) = 0.0009 + 0.0066 + 0.0244 + 0.0588 + 0.1043 + 0.1450 + 0.1648 + 0.1573 = 0.6621[/tex]
0.6621 = 66.21% probability the sample will contain less than 8 defective drives.
d. What is the expected number of defective drives in the sample?
The expected value of the binomial distribution is:
[tex]E(X) = np[/tex]
In this question:
[tex]E(X) = 55(0.12) = 6.6[/tex]
The expected number of defective drives in the sample is 6.6
Determine which type of error is most likely to arise from the following situations. a 1. the time in which individuals are contacted to take a survey occurs during work hours f 2. the last part of a newspaper article asks readers to mail or email the newspaper their opinion about universal health coverage 3. subjects are asked to recall how often they snacked between meals in the past 30 days 4. a survey to assess teachers' opinions about Common Core uses a member list for the largest teachers' union as the sampling frame a. question wording b. undercoverage c. processing error d. bad sampling method e. response error f. nonresponse g. random sampling error
Answer:
Determination of type of error arising from the situations
Situation Type of Error
1. Nonresponse
2. Bad sampling method
3. Question wording
4. Undercoverage
Step-by-step explanation:
Types of errors:
a. question wording means that the manner a question is worded elicits some particular responses, which may not accurately reflect reality.
b. undercoverage occurs when some elements of the target population is not represented on the survey frame.
c. processing error arises from data processing
d. bad sampling method is caused by the voluntariness of those who choose to respond.
e. response error is caused by a questionnaire that requires framing improvements, misinterpretation of questions by interviewers or respondents, and errors in respondents' statements.
f. nonresponse error arises as a result of incomplete information or partial response.
g. random sampling error arises from the limited sample size when compared with the population size.
Help me with this math problem !!!
Answer:
multiply the numerator together and denominator together
Which describes the correlation shown in the scatterplot?
On a graph, points are grouped closely together and increase.
There is a positive correlation in the data set.
There is a negative correlation in the data set.
There is no correlation in the data set.
More points are needed to determine the correlation.
Answer:
More points are needed to determine the correlation.
Answer:
its d
Step-by-step explanation:
;)
The total amount of spending per year, in billions, on pets in a certain country x years after 2000 is given by the following function. P(x)=2.1786+25.2 a) Determine the total amount of spending per year on pets in 2007 and in 2012. b) Find and explain what it represents.
Answer:
40.4502 billion dollars
51.3432 billion dollars
Step-by-step explanation:
Given :
Total amount spent in billions in pets x years after year, 2000 ;
P(x)=2.1786x + 25.2
Amount spent in 2007 ;
x = 2007 - 2000 = 7 years
Put x = 7 in the equation :
P(7)=2.1786(7) + 25.2 = 40.4502
Amount spent in 2012 :
x = 2012 - 2000 = 12 years
Put x = 12 in the equation :
P(12) = 2.1786(12) + 25.2 = 51.3432
The amount spent in billik dollars on pets in :
2007 = $404502 billion
2012 = $51.3432 billion
perimeter of a circle 8 centimeter wide
Answer:
25.13 cm
Step-by-step explanation:
Perimeter ( circumference ) of a circle = 2πr
Given,
The circle is 8 cm wide
which means,
The diameter (d) of the circle is 8 cm.
Radius (r) of the circle = d/2
= 8/2
= 4
Radius = 4 cm
Putting the value in the formula;
2πr
= 2 (22/7) (4)
= 25.13 cm (approx)
A height of 2.5 cm represents 100 goats. What should be the height for 170 goats?
Answer: 4.25
Step-by-step explanation:
2.5/100 = 0.025
0.025 × 170 = 4.25
but the question there is any goats in 2.5 cm ??
that is impossible
Mr. Allway’s math class surveyed all the seventh-grade students to find out their favorite sport. The following circle graph shows a breakdown of the survey findings.
Find the number of degrees represented by Basketball.
108°
101°
11°
140°
Answer:
101 is the answer of the question
Answer:
101 degrees
Step-by-step explanation:
First you add all the percentages
39 + 28 + 30 + 3 = 100%
To find the number of degrees of basketball you multiply 28% by 360 because it’s a circle.
28/100 * 360 = 10,080/100 = 100.8 ~ 101
Mr. Lamb has three children: two girls and one boy. After each meal, one child is chosen at random to wash dishes. Determine the probability that one boy and one girl will wash dishes after lunch and dinner on Saturday.You roll a die twice and add up the dots to get a score. What is the probability that your score is a multiple of 5?
Answer:
1/2 in fractions if you nees it in decimal just transfer
DVD Video Rentals (Refer to Example 3.) The func-
tion V computes the percent share of disc DVD rentals
accounted for by various companies. This function is
defined by V(R) = 37, V(N) = 30, and V(S) = 17,
where R is Redbox, N is Netflix, and S is rental stores.
(Source: Business Insider.)
(a) Write V as a set of ordered pairs.
(b) Give the domain and range of V.
T
Answer:
[tex](a)\ V = \{(N,30),(R,37),(S,17)\}[/tex]
[tex](b)[/tex]
[tex]Domain = \{N,R,S\}[/tex]
[tex]Range = \{37,30,17\}[/tex]
Step-by-step explanation:
Given
[tex]V(R) = 37,\ V(N) = 30,\ V(S) = 17[/tex]
Solving (a): Set of ordered pair
A function y = f(x) is represented as (x,y)
So, the ordered pair of V is:
[tex]V = \{(R,37),(N,30),(S,17)\}[/tex]
Order the alphabets in increasing order
[tex]V = \{(N,30),(R,37),(S,17)\}[/tex]
Solving (b): The domain and the range
In a function [tex]\{(x_1,y_1),...,(x_n,y_n)\}[/tex]
The domain and the range are represented as:
[tex]Domain = \{x_1,x_2....x_n\}[/tex]
[tex]Range = \{y_1,y_2....y_n\}[/tex]
So, we have:
[tex]Domain = \{N,R,S\}[/tex]
[tex]Range = \{37,30,17\}[/tex]
(SAT PREP) Find the value of x in each of the following excersises
Answer:
The answer is 155.
Step-by-step explanation:
We can find the remaining parts of the triangle angles.
Algebra two divide plz help
Answer:
- x³ - 2x² + 3 - 1 / x
Step-by-step explanation:
(4x³ - 8x² + 12x - 4) / (-4x)
- x³ - 2x² + 3 - 1 / x
A population is currently
Answer:
Step-by-step explanation:
The current world population is 7.9 billion as of July 2021 according to the most recent United Nations estimates elaborated by Worldometer. The term "World Population" refers to the human population (the total number of humans currently living) of the world.
NEED HELP ASAPPPPP !!!
Answer:
2160
Step-by-step explanation:
because c is 15 and d is 12 therefore d² is 144 and 144x15 is 2160
Answer:
2160
Step-by-step explanation:
Substitute
[tex](15)(12) {}^{2} [/tex]
[tex]15 \times 144 = 2160[/tex]
Find the surface area of the following triangular prisms
Find the missing side of the triangle
Answer:
x = 7[tex]\sqrt{2}[/tex]
Step-by-step explanation:
Pytago:
[tex]7^2 + 7^2 = x^2\\x = \sqrt{7^2 + 7^2} \\x = 7\sqrt{2}[/tex]
Step-by-step explanation:
In a right triangle, you can find the leg of the triangle by using the Pythagorean theorem.
[tex]a^2+b^2=c^2[/tex]
In this case, we have [tex]7^2+7^2=c^2[/tex], or
[tex]c^2=98[/tex]
[tex]\sqrt{98}[/tex]≅[tex]9.9[/tex]
What is the lengh of the line
Answer:
√45 or 3√5
Step-by-step explanation:
16)dry air is trapped in a narrow uniform glass tube by a mercury pellet of length 25cm .when the tube is placed vertical with the open end um long.what is the external pressure if the column of air becomes 40 cm in length when inverted ? . ( required answer = 74cm hg )
Step-by-step explanation:
Ru Tu yulyryosuyyyhlsgjpcbmb kvjvlcykxnlvdlbvhck
chgkbhlxyovk m.
chchhlzixhvkh
write as a polynomial (-2x^2+x+1)-(x^2-x+7)-(4x^2+2x+8)
Answer:
The answer would be -7x^2 - 14!
Step-by-step explanation:
We can remove the parentheses by distributing the subtraction sign! -2x^2 + x + 1 - x^2 + x - 7 - 4x^2 - 2x - 8. Simplifying this gives us -7x^2 - 14. Hope this helped! :)
I'm stuck. Can anyone help please?
log₉(x - 7) + log₉(x - 7) = 1
2 log₉(x - 7) = 1
log₉(x - 7) = 1/2
Take the base-9 antilogarithm of both sides; in other words, make both sides powers of 9:
[tex]9^{\log_9(x-7)} = 9^{1/2}[/tex]
[tex]9^{1/2}[/tex] can also be written as √9 = 3, and [tex]b^{\log_b(a)}=a[/tex], so the equation reduces to
x - 7 = 3
Solve for x :
x = 10
The profits for video game companies depend on what game platform the game runs on, which can either be a portible system with a built in screen, or a standard system that you have to hook up to a television. The profit off of a portible game system is $72, while the profit from a standard game system is $90. The store manager has to make at least $360 per day in order to keep the store open. Which graph represents this inequality? Write the inequality that represents the number of games that must be sold everyday to meet or beat the sales goal.
Step-by-step explanation:
Can the three values represent the sides of a triangle?
7, 8, √113
Is this a triangle?
If so, what type?
Pythagorean Triple? (yes/no)
no the square root of 113 is rounded to 56x2
find the missing length indicated
Answer:
192
Step-by-step explanation:
geometric mean theorem :
with p and q being the segments of the Hypotenuse, then
h = x = sqrt(p×q)
p = 144
q = 400-144 = 256
h = x = sqrt(144×256) = 12×16 = 192
Select the correct answer.
What is the value of this expression when x = -6 and ?
4(x2 + 3) − 2y
Answer:
D. 157
Step-by-step explanation:
4(x^2+3)-2y
4(6^2+3)-2(-1/2) add in given values
4(39)+1. start with parentheses
156+1. combine like terms
157. answer
Answer:
D. 157
Step-by-step explanation:
Hi there!
We want to find the value of the expression 4(x²+3)-2y is when x=-6 and y=-1/2
Let's first simplify the expression, as that will likely make it easier
Distribute 4 to both x² and 3
4x²+12-2y
That's the expression
Substitute -6 as x into the expression
4(-6)²+12-2y
Raise (-6) to the second power
4*36+12-2y
Multiply 36 by 4
144+12-2y
Add 12 and 144 together
156-2y
Now the expression is 156-2y
But remember that we know that y=-1/2, and we haven't substituted it into the expression yet
Substitute -1/2 as y into the expression
156-2(-1/2)
Multiply
156+2/2
Simplify
156+1
Add
157
Hope this helps!
What is the value of x?
2
3
6
7
Answer:
i think 3
Step-by-step explanation:
Answer: [A] 2
Step-by-step explanation:
100% on edge 2023
if the Arithmetic means of the 17 numbers is 14. when the two numbers are eliminated the mean becomes 13 if the differences of the two eliminated numbers is 7. find the numbers.
Answer=30,20 but show me in process.
Answer:
The numbers are 18 and 25
Step-by-step explanation:
Given
[tex]\bar x_1 = 14[/tex] [tex]n_1 = 17[/tex]
[tex]\bar x_2 = 13[/tex] [tex]n_2 = 15[/tex]
[tex]a - b = 7[/tex] --- the difference of the 2 numbers
Required
Find a and b
We have:
[tex]\bar x = \frac{\sum x}{n}[/tex] -- mean formula
So, we have:
[tex]\bar x_1 = \frac{\sum x_1}{n_1}[/tex]
[tex]14 = \frac{\sum x_1}{17}[/tex]
Cross multiply
[tex]\sum x_1 = 14 * 17[/tex]
[tex]\sum x_1 = 238[/tex]
When the two numbers are removed, we have:
[tex]\bar x_2 = \frac{\sum x_2}{n_2}[/tex]
[tex]13 = \frac{\sum x_2}{15}[/tex]
Cross multiply
[tex]\sum x_2 = 13 * 15[/tex]
[tex]\sum x_2 = 195[/tex]
The two numbers that were removed are:
[tex]a + b = \sum x_1 - \sum x_2[/tex]
[tex]a + b = 238 - 195[/tex]
[tex]a + b = 43[/tex]
Make a the subject
[tex]a= 43 - b[/tex]
We have:
[tex]a - b = 7[/tex]
Substitute [tex]a= 43 - b[/tex]
[tex]43 - b - b = 7[/tex]
[tex]43 - 2b = 7[/tex]
Collect like terms
[tex]2b = 43 - 7[/tex]
[tex]2b = 36[/tex]
Divide by 2
[tex]b = 18[/tex]
Substitute [tex]b = 18[/tex] in [tex]a= 43 - b[/tex]
[tex]a = 43 - 18[/tex]
[tex]a = 25[/tex]
Write a quadratic function f whose zeros are 4 and 1
9514 1404 393
Answer:
f(x) = (x -4)(x -1)
Step-by-step explanation:
If 'a' is a zero of the function, then (x -a) is a factor. The two zeros mean the factored form of the quadratic is ...
f(x) = (x -4)(x -1)
__
The expanded form will be ...
f(x) = x² -5x +4
find an odd natural numbers x such that LCM (x, 40) = 1400
Answer:
175
Step-by-step explanation:
so, the LCM is the combination of the longest chains of the prime factors in every number.
40 : 2, 2, 2, 5
1400 / 40 = 35
35 : 5, 7
but LCM(35, 40) = 2×2×2×5×7 = 280
and not 1400.
what is missing ?
1400 / 280 = 5
aha, another prime factor 5 is missing to get 1400.
x : 5, 5, 7
so, x = 5×5×7 = 175
LCM(175, 40) = 2×2×2×5×5×7 = 1400
when 18 is subtracted from six times a certain number the result is 96 what is the number
Let the number be x
ATQ
[tex]\\ \sf\twoheadrightarrow 6x-18=96[/tex]
[tex]\\ \sf\twoheadrightarrow 6x=96+18[/tex]
[tex]\\ \sf\twoheadrightarrow 6x=112[/tex]
[tex]\\ \sf\twoheadrightarrow x=\dfrac{112}{6}[/tex]
[tex]\\ \sf\twoheadrightarrow x=7[/tex]
