AnswersStatisticsPreparing to Conduct a Chi-Square Test for Goodness of Fit

Preparing to Conduct a Chi-Square Test for Goodness of Fit — Quiz Answers

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3

As products come off a large assembly line, they are inspected for quality. They are placed into one of three categories: pass, fail, or need additional inspection. The manager claims that 80 percent of the products pass the inspection, 5 percent fail, and 15 percent need additional inspection. In an effort to increase the passing rate, the machines are recalibrated. After this recalibration, a random sample of 100 products is selected. The manager would like to know if there is convincing evidence that the distribution has changed. What are the appropriate hypotheses?

A
cap h sub 0 : p sub pass is equal to 0 point 8 0 , p sub fail is equal to 0 point 0 5 , p sub inspection is equal to 0 point 1 5 cap h sub A : Not all of the p sub i's are as stated.
B
cap h sub 0 : p sub pass is equal to 0 point 8 0 , p sub fail is equal to 0 point 0 5 , p sub inspection is equal to 0 point 1 5 cap h sub A : p sub pass is greater than 0 point 8 0 , p sub fail is less than 0 point 0 5 , p sub inspection is not equal to 0 point 1 5
C
cap h sub 0 : p sub pass is equal to 0 point 8 0 , p sub fail is equal to 0 point 0 5 , p sub inspection is equal to 0 point 1 5 cap h sub A : p sub pass is not equal to 0 point 8 0 , p sub fail is not equal to 0 point 0 5 , p sub inspection is not equal to 0 point 1 5
D
cap h sub 0 : p sub pass is equal to 0 point 8 0 , p sub fail is equal to 0 point 0 5 , p sub inspection is equal to 0 point 1 5 cap h sub A : p sub pass is greater than 0 point 8 0 , p sub fail is less than 0 point 0 5 , p sub inspection is less than 0 point 1 5
4

A prize wheel at a carnival consists of five equal sectors of these colors: red, blue, green, yellow, and orange. If the wheel lands on yellow, the player wins a prize. After observing several spins, a customer suspects that the wheel is not fair. To substantiate this belief, the customer observes 100 consecutive spins of the prize wheel. What are the appropriate hypotheses?

A
cap h sub 0 : The wheel is fair. cap h sub A : The wheel is not fair.
B
cap h sub 0 : The wheel will not land on red 20 times, blue 20 times, green 20 times, yellow 20 times, and orange 20 times. cap h sub A : The wheel will land on red 20 times, blue 20 times, green 20 times, yellow 20 times, and orange 20 times.
C
cap h sub 0 : The wheel is not fair. cap h sub A : The wheel is fair.
D
cap h sub 0 : The wheel will land on red 20 times, blue 20 times, green 20 times, yellow 20 times, and orange 20 times. cap h sub A : The wheel will not land on red 20 times, blue 20 times, green 20 times, yellow 20 times, and orange 20 times.
5

According to a government website, 42 percent of US citizens are Democrats, 34 percent are Republicans, and 24 percent are Independents. A local municipality would like to know if the distribution of political party affiliation among its citizens differs from the nationwide percentages. A random sample of 500 citizens of the municipality is selected. What are the appropriate hypotheses?

A
cap h sub 0 : The distribution of political party in the municipality is 42 percent Democrat, 34 percent Republican, and 24 percent Independent. cap h sub A : The distribution of political party in the municipality is not 42 percent Democrat, 34 percent Republican, and 24 percent Independent.
B
cap h sub 0 : The sample will not contain 210 Democrats, 170 Republicans, and 120 Independents. cap h sub A : The sample will contain 210 Democrats, 170 Republicans, and 120 Independents.
C
cap h sub 0 : The sample will contain 210 Democrats, 170 Republicans, and 120 Independents. cap h sub A : The sample will not contain 210 Democrats, 170 Republicans, and 120 Independents.
D
cap h sub 0 : The distribution of political party in the municipality is not 42 percent Democrat, 34 percent Republican, and 24 percent Independent. cap h sub A : The distribution of political party in the municipality is 42 percent Democrat, 34 percent Republican, and 24 percent Independent.
7

An employee claims that 20 percent of the email she receives is personal, 60 percent is work related, and 20 percent is spam. The high level of spam she is receiving is frustrating, so she creates some new filters. She then selects a random sample of 50 emails over the next several weeks. She would like to know if the distribution of emails she receives has changed. What are the appropriate hypotheses?

A
cap h sub 0 : The distribution of emails received is still 20 percent personal, 60 percent work related, and 20 percent spam. cap h sub A : The distribution of emails received is no longer 20 percent personal, 60 percent work related, and 20 percent spam.
B
cap h sub 0 : The distribution of emails received is still 20 percent personal, 60 percent work related, and 20 percent spam. cap h sub A : She now receives less than 20 percent spam.
C
cap h sub 0 : The distribution of emails received is still 20 percent personal, 60 percent work related, and 20 percent spam. cap h sub A : She now receives an amount different from 20 percent spam.
D
cap h sub 0 : The distribution of emails received is no longer 20 percent personal, 60 percent work related, and 20 percent spam. cap h sub A : The distribution of emails received is still 20 percent personal, 60 percent work related, and 20 percent spam.
8

It is common knowledge that a fair coin lands heads up 50 percent of the time and tails up 50 percent of the time. For fair coins, a probability of 0 is assigned to the coin landing on its edge. But what if several coins were glued together? A teacher claims that if 10 pennies were glued together and flipped many times, the penny stack would land on heads 25 percent of the time, tails 25 percent of the time, and on its edge 50 percent of the time. To investigate this claim, a student glues 10 pennies together and flips the stack 200 times. The student would like to know if there is convincing evidence that the distribution differs from what the teacher claimed. What are the appropriate hypotheses?

A
cap h sub 0 : The distribution of flips is 25 percent heads, 25 percent tails, and 50 percent edge. cap h sub A : The distribution of flips is not 25 percent heads, 25 percent tails, and 50 percent edge.
B
cap h sub 0 : The distribution of flips is not 25 percent heads, 25 percent tails, and 50 percent edge. cap h sub A : The distribution of flips is 25 percent heads, 25 percent tails, and 50 percent edge.
C
cap h sub 0 : The penny stack will not land on heads 50 times, tails 50 times, and on its edge 100 times when flipped 200 times. cap h sub A : The penny stack will land on heads 50 times, tails 50 times, and on its edge 100 times when flipped 200 times.
D
cap h sub 0 : The penny stack will land on heads 50 times, tails 50 times, and on its edge 100 times when flipped 200 times. cap h sub A : The penny stack will not land on heads 50 times, tails 50 times, and on its edge 100 times when flipped 200 times.
9

Students at a large university have four places to get lunch: the cafeteria, the hut, the taco wagon, or the pizza place. An article in the school newsletter states that 70 percent of students prefer to get lunch in the cafeteria and the other three options are preferred equally. To investigate this claim, a random sample of 150 students is selected. What are the appropriate hypotheses?

A
cap h sub 0 : The distribution of lunch preferences is 70 percent cafeteria, 10 percent hut, 10 percent taco wagon, and 10 percent pizza place. cap h sub A : The distribution of lunch preferences is not 70 percent cafeteria, 10 percent hut, 10 percent taco wagon, and 10 percent pizza place.
B
cap h sub 0 : In the sample of 150 students, the distribution will not be that 105 will prefer the cafeteria, 15 will prefer the hut, 15 will prefer the taco wagon, and 15 will prefer the pizza place. cap h sub A : In the sample of 150 students, 105 will prefer the cafeteria, 15 will prefer the hut, 15 will prefer the taco wagon, and 15 will prefer the pizza place.
C
cap h sub 0 : In the sample of 150 students, 105 will prefer the cafeteria, 15 will prefer the hut, 15 will prefer the taco wagon, and 15 will prefer pizza place. cap h sub A : In the sample of 150 students, the distribution will not be that 105 will prefer the cafeteria, 15 will prefer the hut, 15 will prefer the taco wagon, and 15 will prefer the pizza place.
D
cap h sub 0 : The distribution of lunch preferences is not 70 percent cafeteria, 10 percent hut, 10 percent taco wagon, and 10 percent pizza place. cap h sub A : The distribution of lunch preferences is 70 percent cafeteria, 10 percent hut, 10 percent taco wagon, and 10 percent pizza place.

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