1.Employees of a certain company took a mean of 7.1vacation days in 2020. The CEO of the company believes that in 2021the average number of sick days was less than 7.1. A sample of 55employees took a mean of 6.6days in 2021, is known to be equal to 1.4. At = 0.02, test the CEO's claim. a 1-6) Give the hypotheses for H₀ (a1, a2 and a3) and H₁ (a4, a5 and a6) H₀ a1) or p

a2) =,, or

a3)

H₁ a4) or p

a5), >, or <

a6)

b) Calculate the test statistic. z = _______ (Round your answer to 3 decimals.) c 1-3) Formulate the decision rule for the critical value approach. RejectH₀if c1) zor p

c2) < or >

c3)

d 1) Make a decision. d1) Reject Ho orDo not reject Ho

e1-2) Give your conclusion. At = .___, there (is/is not) enough evidence to conclude that in 2021the average number of sick days was less than 7.1.

e1)

e2) is or is not

2.A provost thinks that the mean age of students at his college is not 21.8, like it was last school year. In a random sample of 20students, the mean age was 22.5and the standard deviation was 1.6. Test the provost's claim. Use = 0.10.

a 1-6) Give the hypotheses for H₀ (a1, a2 and a3) and H₁(a4, a5 and a6)

H₀ a1) or p

a2) =, ,

a3)

H₁ a4) or p

a5) , >, <

a6)

b) Calculate the test statistic. t = _____ (Round your answer to 3 decimals.)

c 1-3) Formulate the decision rule for the critical value approach.

Reject H₀ if (c1 c2 c3)

c1) |t|or|p|

c2) >or <

c3)

d 1) Make a decision(d1). d1) reject Ho or do not reject Ho

e1-2) Give your conclusion. At = .___, there (is/is not) enough evidence to conclude that the mean age of students at his college is not 21.8, like it was last school year. e1)

e2) is or is not

3.A professor thinks that the mean number of hours that students study the night before a test is 2.75. He selected a random sample of 10students and found that the mean number of study hours was 3.78and the standard deviation is 1.47hours. Test the professor's claim at = 0.01.

a 1-6) Give the hypotheses for H₀ (a1, a2 and a3) and H1 (a4, a5 and a6)

H₀ a1) or p

pClick for List a2) =,,

=Click for List a3)

H₁ a4) or p

pClick for List a5) , >, <

>

b) Calculate the test statistic. t = _______ (Round your answer to 3 decimals.)

c 1-3) Formulate the decision rule for the p value approach.

Reject H₀ if (c1,c2,c3) c1) t or p

c2) > or <

c3)

d 1-2) Give the p value (d1 round to 2 decimals) < p < (d2 - round to 2 decimals) and make a decision (d3). d1)

d2)

d3) reject Ho or do not reject Ho

e1-2) Give your conclusion. At = .___, there (is/is not) enough evidence to conclude that the mean number of hours that students study the night before a test is not 2.75.

e1)

e2) is or is not

4.The International Dairy Foods Association (IDFA) believes that the average daily amount of calcium that teenagers consume is greater than 995mg. A random sample of 45teenagers had an average of 1001mg. The population standard deviation is known to be equal to 36.2mg. Test to see if the average daily amount of calcium that teenagers consume is greater than 995mg by using = 0.025.

a 1-6) Give the hypotheses for H₀ (a1, a2 and a3) and H₁ (a4, a5 and a6)

H₀ a1) or p

a2) =,,

a3)

H₁ a4) or p

a5) , >, <

a6)

b) Calculate the test statistic. z = _________ (Round your answer to 3 decimals.)

c 1-3) Formulate the decision rule for the p value approach. Reject H₀ if (c1,c2,c3)

c1) z or p

c2) < or >

c3)

d 1-2) Give the p value (d1 - round to 3 decimals) and make a decision (d2). d1)

d2) reject Ho or do not reject Ho

e1-2) Give your conclusion. At = ._____, there (is/is not) enough evidence to conclude that the average daily amount of calcium that teenagers consume is greater than 995mg. e1)

e2) is or is not

5. For problems 6 through 10, the assumptions and conditions for inference are met. A major airline company thinks that the proportion of its customers who are satisfied with the service of the airline is greater than .894. In a random sample of 1250 customers, 1145customers said that they were satisfied with the airline's service. Test the airline company's claim. Use = 0.05.

a 1-6) Give the hypotheses for H₀ (a1, a2 and a3) and H₁ (a4, a5 and a6)

H₀ a1) or p

a2) =,,

a3)

H₁ a4) or p

a5), >, <

a6)

b) Calculate the test statistic. z = _________ (Round your answer to 3 decimals.)

c 1-3) Formulate the decision rule for the critical value approach.

Reject H₀ if (c1,c2,c3)

c1) z or p

c2) < or >

c3)

d) Make a decision(d1). d1) reject Ho or do not reject Ho

e1-2) Give your conclusion. At = .____, there (is/is not) enough evidence to conclude that the proportion of its customers who are satisfied with the service of the airline is greater than .894. e1)

e2) is or is not

6.In 2015, the average GPAof incoming freshman was 2.34. The provost wants to perform a significance test to determine whether the average GPAof incoming freshman has increased since 2015. The hypotheses are:

H₀: 2.34 H₁: > 2.34

Suppose that the results of the sample lead to a nonrejection of the null hypothesis. Classify that decision as a Type I error, a Type II error, or a correct decision, if in fact the average g. p. a. of incoming freshman hasincreased since 2015.

		Type I error
		Type II error
		Correct decision

7. When is it appropriate to use in the hypotheses?

		c) when you are conducting a 1-proportion z test
		a) when you are conducting a z test
		d) both a and b are true
		b) when you are conducting a t test

8.Rejecting a trueH₀

		is the correct decision.
		is a Type II error.
		is a Type I error.

9.Rejecting a false H₀

		is the correct decision.
		is a Type I error.
		is a Type II error.

10.

A manufacturer has indicated that the mean amount of soda in its 32-ounce bottles is 32.2 ounces. A consumer advocacy group wants to perform a significance test to determine whether the mean amount is really less than 32.2 ounces.

		Two-tailed
		Left-tailed
		Right-tailed