Question

2. Fall temperatures in San Diego (measured on the Celsius Scale ℃) result in summary statistics:

n=30

x = 22.30 ℃

s = 1.38 ℃

Use a 0.01 significance level to test the claim that the mean summer temperature in San Diego is less than 25.8 ℃. Use the critical value method for testing the claim. Assume temperatures are approximately normally distributed.

a. Fill in the table completely with justification. Solution:

H0:

H1:

State whether the test is two-tailed, left-tailed or right-tailed and justify.

The value of α =

Write the formula for the appropriate test statistic and justify:

The value of the P-value=

Critical value(s) =

b. State the conclusion that addresses the original claim. Solution:

c. Assume the population standard deviation σ is known to be 1.55 ℃. Identify the test statistic. Use the P-value method to conduct the hypothesis test. Does your conclusion agree with your result in (b)? Solution:

3. A Verizon survey of 400 smartphone users showed that 210 of them said that their smartphone is the only thing they could not live without. Use a 0.05 level of significance to test the claim that more than half of smartphone users identify the smartphone as the only thing they could not live without.

a. State: H0 and H1, the test statistic, p-value and critical value(s). Solution:

H0:

H1:

State whether the test is two-tailed, left-tailed or right-tailed.

The value of α =

Write the formula for the appropriate test statistic:

The value of the P-value=

Critical value(s) =

b. State the conclusion that addresses the original claim. Solution:

Answer 1

Question 2:

a)

c)

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