# STATS Quiz 4 problems

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Question 1 of 20 1.0 Points

Which of the following values is not typically used for ?

A.0.01

B.0.10

C.0.50

D.0.05

Question 2 of 20 1.0 Points

A null hypothesis can only be rejected at the 5% significance level if and only if:

A.the null hypotheses includes sampling error

B.the null hypothesis is biased

C.a 95% confidence interval does not include the hypothesized value of the parameter

D.a 95% confidence interval includes the hypothesized value of the parameter

Question 3 of 20 1.0 Points

A severe storm has an average peak wave height of 16.4 feet for waves hitting the shore. Suppose that a storm is in progress with a severe storm class rating. Let us say that we want to set up a statistical test to see if the wave action (i.e., height) is dying down or getting worse. If you wanted to test the hypothesis that the waves are dying down, what would you use for the alternate hypothesis? Is the P-value area on the left, right, or on both sides of the mean?

A. H1: is not equal to 16.4 feet; the P-value area is on the right of the mean

B. H1: is less than 16.4 feet; the P-value area is on the left of the mean

C. H1: is greater than 16.4 feet; the P-value area is on both sides of the mean

D. H1: is greater than 16.4 feet; the P-value area is on the left of the mean

Question 4 of 20

The “Pizza Hot” manager commits a Type I error if he/she is

A.switching to new style when it is no better than old style

B.staying with old style when new style is no better than old style

C.staying with old style when new style is better

D.switching to new style when it is better than old style

Question 5 of 20

The hypothesis that an analyst is trying to prove is called the:

A.level of significance

B.quality of the researcher

C.elective hypothesis

D.alternative hypothesis

Question 6 of 20 1.0 Points

Results from previous studies showed 79% of all high school seniors from a certain city plan to attend college after graduation. A random sample of 200 high school seniors from this city reveals that 162 plan to attend college. Does this indicate that the percentage has increased from that of previous studies? Test at the 5% level of significance.

State the null and alternative hypotheses.

A.H0: p = .79, H1: p ≠ .79

B.H0: = .79, H1: > .79

C.H0: p ≤ .79, H1: p > .79

D. H0: = .79, H1: > .79

Question 7 of 20

In an article appearing in Today’s Health a writer states that the average number of calories in a serving of popcorn is 75. To determine if the average number of calories in a serving of popcorn is different from 75, a nutritionist selected a random sample of 20 servings of popcorn and computed the sample mean number of calories per serving to be 78 with a sample standard deviation of 7.

At the = .05 level of significance, does the nutritionist have enough evidence to reject the writer’s claim?

A.Cannot Determine

B.No

C.Yes

Question 8 of 20

A.z = 1.96

B.z = 0.62

C.t = 1.645

D.z = 0.69

Question 9 of 20

A type I error occurs when the:

A.test is biased

B.sample mean differs from the population mean

C.null hypothesis is incorrectly rejected when it is true

D.null hypothesis is incorrectly accepted when it is false

Question 10 of 20 1.0 Points

In an article appearing in Today’s Health a writer states that the average number of calories in a serving of popcorn is 75. To determine if the average number of calories in a serving of popcorn is different from 75, a nutritionist selected a random sample of 20 servings of popcorn and computed the sample mean number of calories per serving to be 78 with a sample standard deviation of 7.

Compute the z or t value of the sample test statistic.

A.z = 1.916

B.t = -1.916

C.z = 1.645

D.t = 1.916

Question 12 of 20 1.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.

Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.

For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

A survey determines that mint chocolate chip is the favorite ice cream flavor of 6% of consumers. An ice cream shop determines that of 190 customers, 15 customers stated their preference for mint chocolate chip.

Find the P-value that would be used to determine if the percentage of customers who prefer mint chocolate chip ice has increased at a 5% level of significance.

P-value: 0.1357 Round your answer to four decimal places as necessary.

Question 13 of 20 1.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.

Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.

For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

A statistician wishes to test the claim that the standard deviation of the weights of firemen is greater than 25 pounds. To do so, she selected a random sample of 20 firemen and found s = 27.2 pounds.

Assuming that the weights of firemen are normally distributed, to test her research hypothesis the statistician would use a chi-square test. In that case, what is the computed test value?

Place your answer, rounded to 3 decimal places, in the blank. For example, 23.456 would be a legitimate entry. 22.491

Question 14 of 20 1.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.

Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.

For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

Suppose a firm that produces light bulbs wants to know whether it can say that its light bulbs typically last more than 1500 hours. Hoping to find support for their claim, the firm collects a random sample of n = 25 light bulbs and records the lifetime (in hours) of each bulb. The information related to the hypothesis test is presented below.

Test of H0: 1500 versus H1: > 1500

Sample mean 1509.5

Std error of mean 4.854

What is the test value that you would use to conduct this test? Place your answer, rounded to 3 decimal places in the blank. For example, 1.234 would be a legitimate entry. 1.957

Question 15 of 20

Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.

For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

A firm that produces light bulbs claims that their lightbulbs last 1500 hours, on average. You wonder if the average might differ from the 1500 hours that the firm claims. To explore this possibility you take a random sample of n = 25 light bulbs purchased from this firm and record the lifetime (in hours) of each bulb. You then conduct an appopriate test of hypothesis. Some of the information related to the hypothesis test is presented below.

Test of H0: = 1500 versus H1: 1500

Sample mean 1509.5

Std error of mean 4.854

Assuming the life length of this type of lightbulb is normally distributed, what is the p-value associated with this test? Place your answer, rounded to 3 decimal places, in the blank. For example, 0.234 would be a legitimate entry. 0.031

Question 16 of 20 1.0 Points

Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.

For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

A survey determines that mint chocolate chip is the favorite ice cream flavor of 6% of consumers. An ice cream shop determines that of 240 customers, 18 customers stated their preference for mint chocolate chip.

Find the P-value that would be used to determine if the percentage of customers who prefer mint chocolate chip ice has increased at a 5% level of significance.

P-value: 0.1639 round your answer to four decimal place as necessary

Question 17 of 20 1.0 Points

Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.

For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

The CEO of a software company is committed to expanding the proportion of highly qualified women in the organization’s staff of salespersons. He believes that the proportion of women in similar sales positions across the country is less than 45%. Hoping to find support for his belief, he directs you to test

H0: p .45 vs H1: p < .45.

In doing so, you collect a random sample of 50 salespersons employed by his company, which is thought to be representative of sales staffs of competing organizations in the industry. The collected random sample of size 50 showed that only 18 were women.

Compute the p-value associated with this test. Place your answer, rounded to 4 decimal places, in the blank. For example, 0.3456 would be a legitimate entry. 0.1003

Question 18 of 20 1.0 Points

If a null hypothesis about a population proportion p is rejected at the 0.025 level of significance, then it must also be rejected it at the 0.05 level.

True

False

Question 19 of 20 1.0 Points

The smaller the p–value, the more evidence there is in favor of the alternative hypothesis.

True

False

Question 20 of 20 1.0 Points

A one-tailed alternative is one that is supported by evidence in either direction.

True

False

- 7 years ago

**STATS Quiz 4 problems with Solution**

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### Statistics Quiz

NOT RATEDQuestion 1 of 20

1.0 PointsThe form of the alternative hypothesis can be:

A.one-tailed

B.two-tailed

C.neither one nor two-tailed

D.one or two-tailed

Question 2 of 20

1.0 PointsA lab technician …

7 years ago