Question

At a certain grocery store 65% of the customers regularly use coupons.

What is the approximate standard deviation of the sampling distribution of the proportion for

samples of size 340?

A.11.1%

B.6.7%

C.4.4%

D.2.6%

Answer 1

D

Explanation:

BECAUSE

WHEN

YOU

LOOK

AT

A

B

OR

C

OH

NO

THERE

IS

NO

MORE

SPACE

!!!!!!!!!!!!!!

Answer 2

Option D 2.6% is right.

Explanation:

Given that at a certain grocery store 65% of the customers regularly use coupons.

Proportion of the customers regularly use coupons.=0.65

Proportion of customers who do not regularly use coupons.

=1-0.65 = 0.35

Sample size = 340

In usual notation we write this as

`p=0.65\\q=0.35\\n = 340`

Std deviation =
`\sqrt{(pq)/(n) } \\=\sqrt{(0.65*0.35)/(340) } \\=0.025867`

In percentage this can be written as 2.5867% ~2.6%

Option D 2.6% is right.