According to a survey in a country, 21% of adults do not own a credit card. Suppose a simple random sample of 400 adults is obtained.

(a) Describe the sampling distribution of Modifying Above p with caret p, the sample proportion of adults who do not own a credit card. Choose the phrase that best describes the shape of the sampling distribution of Modifying Above p with caret p below.

B.

Approximately normal because n0.05N and np (1p)10

Your answer is correct.

Determine the mean of the sampling distribution of Modifying Above p with caret p.

mu Subscript Modifying Above p with caret Baseline equals

p=______.

Determine the mean of the sampling distribution of Modifying Above p with caret p. mu Subscript Modifying Above p with caret Baseline equals

p= 0.21

(Round to two decimal places asneeded.)

Determine the standard deviation of the sampling distribution of Modifying Above p with caret p.

sigma Subscript ModifyingAbove p with caret p= 0.020

(Round to three decimal places asneeded.)

(b) What is the probability that in a random sample of 400 adults, more than 23% do not own a creditcard?

The probability is 0.1587.

(Round to four decimal places asneeded.)

If 100 different random samples of 400

400 adults wereobtained, one would expect

16

16 to result in more than 23

23% not owning a credit card.

(Round to the nearest integer asneeded.)

(c) What is the probability that in a random sample of 400 adults, between 18% and 23% do not own a creditcard?

The probability is______.

(Round to four decimal places asneeded.)