Question

(4 pts) According to a recent article, 32% of drivers had driven drowsy in the past month. (Source: Thenationshealth.aphapublications.org/content/41/10/E52.fuII)

Suppose law enforcement officials are planning a survey of 1000 drivers to determine what proportion are driving drowsy.

1. Is whether a driver has driven drowsy in the past month qualitative or quantitative?

2. Would it be unusual if, in a random sample of 1000 drivers, 35% or more were driving drowsy in the last month? Include justifications for full credit.

3. What is the minimum number of drivers that must be sampled to be sure that the shape is approximately normal? Hint – use the formula

Answer 1

Ans:

1)Qualitative

2)

z=(0.35-0.32)/sqrt(0.32*(1-0.32)/1000)

z=2.03

P(z>2.03)=0.0210

Yes,unusual as above probability is less than 0.05

3)

np>=10

n*0.35>=10

n>=10/0.35

n>=29 approximately