7/27/2019 m62 Stat Sample

1/8

Math 62 Statistics Sample Exam Questions

1. (10) Explain the difference between the distribution of a population and the sampling distributionof a statistic, such as the mean, of a sample randomly selected from that population.

2. (10) Select a sample of size n = 10 from a normal population. For what value t0 will Pr[t < t0] = 0.01?

t0 =

Show your work:

1

7/27/2019 m62 Stat Sample

2/8

3. (10) The duration of Alzheimers disease ranges from 3 to 20 years. The average is 8 years and thestandard deviation is 4 years. For a clinical study 30 patients are randomly selected that have beendetermined to be at the very beginning stage of the disease.

(a) What is the probability that the average duration of the disease among the sampled patientswill be less than 7 years?

Probability =

(b) What is the probability that the average duration of the disease among the sampled patients

will be between 7 and 9 years?

Probability =

2

7/27/2019 m62 Stat Sample

3/8

4. (10) A random sample of 985 likely voters was taken. 592 indicated that they approved of a reductionin the federal income tax. Construct a 95% confidence interval for the true proportion p of voterswho approve of reducing the income tax.

< p