Question

A survey was conducted that asked 1004 people how many books they had read in the past year. Results indicated that x overbarequals12.5 books and sequals16.6 books. Construct a 95​% confidence interval for the mean number of books people read. Interpret the interval.

Answer 1

Answer:

Step-by-step explanation:

Given that a survey was conducted that asked 1004 people how many books they had read in the past year.

Results are:

x bar =12.5

s = 16.6

n = 1004

Std error of sample = $\frac{s}{\sqrt{n-1} } =\frac{16.6}{\sqrt{1003} }\\=0.524152\\=0.524$

Since population std dev is not known t critical value can be used for confidence interval.

df = 1004-1 =1003

t critical = 1.96

Margin of error $= 1.96(std error) =1.027$

Confidence interval lower bound $= 12.5-1.027 = 11.473$

Upper bound $= 12.5+1.027 = 13.527$