Question

1. Write H₀ and H_A in notation for each of the following research questions, and determine whether the hypothesis test for each research question will be left-tailed, right-tailed, or two-tailed:

1. An urban planner claims that the noontime mean traffic flow rate on a busy downtown college campus is 35 cars per minute.

Null Hypothesis (H0)	Alternative Hypothesis (HA)	Left-Tailed, Right-Tailed, or Two-Tailed?

2. A cell phone repair shop advertises that the mean cost of repairing a phone screen is less than $75.

Null Hypothesis (H0)	Alternative Hypothesis (HA)	Left-Tailed, Right-Tailed, or Two-Tailed?

3. An amusement park claims that the mean daily attendance of the park is at least 20,000 people.

Null Hypothesis (H0)	Alternative Hypothesis (HA)	Left-Tailed, Right-Tailed, or Two-Tailed?

4. A tablet manufacturer claims that the mean life of the battery for a certain model of tablet is more than 8 hours.

Null Hypothesis (H0)	Alternative Hypothesis (HA)	Left-Tailed, Right-Tailed, or Two-Tailed?

5. A polling organization reports that the number of responses to a survey mailed to 100,000 U.S. residents is not equal to 100,000.

Null Hypothesis (H0)	Alternative Hypothesis (HA)	Left-Tailed, Right-Tailed, or Two-Tailed?

Answer 1

a.

H0: =35 cars per minute

HA: 35 cars per minute

(where, =Population mean of noontime traffic flow rate).

It is a Two-Tailed test.

b.

H0: $75

HA: < $75

(where, =Population mean cost of repairing a phone screen).

It is a Left-Tailed test.

c.

H0: < 20,000

HA: 20,000

(where, =Population mean daily attendance of the park).

It is a Right-Tailed test.

d.

H0: 8 hours

HA: > 8 hours

(where, =Population mean life of the battery).

It is a Right-Tailed test.

e.

Proportion =100,000/100,000 =100% =1

H0: P =1

HA: P 1

(where, P =Population proportion of the number of responses to the survey mailed to 100,000 U.S. residents).

It is a Two-Tailed test.