Q:

Refer to the accompanying TI-83/84 Plus calculator display of a 95% confidence interval. The sample display results from using a simple random sample of the amounts of tar (in milligrams) in cigarettes that are all king size, nonfiltered, nonmenthol, and non-light. Express the confidence interval in the format of mean + or - E.ZInterval(23.305,25.075)mean=23.69n = 30The confidence interval is __?__ +or-___?___.

Accepted Solution

A:
Answer:The confidence interval is [tex]22.805<\mu<24.575[/tex]Step-by-step explanation:We have given, The Z interval (23.305,25.075) Β  Mean [tex]\bar{x}=23.69[/tex]Sample n=30To find : The confidence interval?Solution : We know, The confidence interval is in the format of [tex]\bar{x}-E<\mu<\bar{x}+E[/tex]E denotes the margin of error,[tex]E=\frac{U-L}{2}[/tex]Where, U is the upper limit U=25.075L is the lower limit L=23.305[tex]E=\frac{25.075-23.305}{2}[/tex][tex]E=\frac{1.77}{2}[/tex][tex]E=0.885[/tex]Substitute the value of E and [tex]\bar{x}[/tex] in the formula,[tex]23.69-0.885<\mu<23.69+0.885[/tex][tex]22.805<\mu<24.575[/tex]Therefore, The confidence interval is [tex]22.805<\mu<24.575[/tex]