A random sample of 100 recorded deaths in the United States during the past year showed an average life span of 71.8 years. Assuming a population standard deviation of 8.9 years, does this seem to indicate that the mean life span today is greater than 70 years?

Null Hypothesis: The mean life span today is 70 years.

1. The null hypothesis stated in symbols is _____.

A. H0:=70

B. H0:=71.8

C. H0:>70

Your answer:

Alternative Hypothesis: The mean life span today is greater than 70 years.

1. The alternative hypothesis stated in symbols is _____.

A. H1:>70

B. H1:70

C. H1:=71.8

Your answer:

1. What is the descriptive statistics from the problem _____?

A. =70

B. x=71.8

C. x=70

D. =71.8

Your answer:

1. After we compare the observed sample result with the distribution assuming the null hypothesis is true, we get p value is close to zero.

A. We reject the null hypothesis as p value is too small. The average life span is very likely to be greater than 70 years.

B. We can not reject the null hypothesis as p value is too small. The average life span is very likely to be 70 years.

Your answer:

1. Decide based on the hypothesis test that the mean life span is greater than 70 years, but in reality the mean life span is 70 years.

A. This is Type I error.

B. This is Type II error

Your answer: