Question

1. Which description best describes the process of how a significance test works?

a) We start by believing the null hypothesis, but then try to prove it wrong

b) Wes tart by believing neither hypothesis, and see which hypothesis our data agrees with

c) We start by believing the alternative hypothesis, but then try to prove it wrong

2. Which of the following is the MOST important requirement for all confidence intervals and significance tests.

a) normal population

b) STS

c) know σ

d) large enough sample

3. You want to estimate the average speed of drivers along a certain stretch of I-5. You take a sample of 20 cars and find that their average speed is 72.4 miles per hour. The number 72.4 in this example is which of the following?

a) statistic

b) neither

c) parameter

d) both

4. You are running a significance test with the following information. Find the p-value for this test. (do not round)

H0: p =0.37

Ha: 0>0.37

p =0.5

n=10

z=0.85

Answer 1

(1)

Correct option:

a) We start by believing the null hypothesis, but then try to prove it wrong

Explanation:

In Hypothesis Testing, we first assume the null hypothesis to be true. If the calculated value of Test Statistic is greater than critical value, the difference is significant. Reject null hypothesis. If the calculated value of Test Statistic is less than critical value, the difference is not significant. Fail to reject null hypothesis.

(2)

Correct option:

(b) SRS

Explanation:

The MOST important requirement for all confidence intervals and significance tests is SRS (Simple Random Sampling): The method of sampling should be such that every sampling unit has an equal chance of being chosen.

(3)

Correct option:

a) statistic

Explanation:

72.4 miles per hour is the characteristic of a sample and so it is a statistic.

(4)

Given:
Z score = 0.85

One Tail - Right Side Test

By Technology, p value = 0.1977

So,

p - value = 0.197663