Astudy of 420 comma 100 cell phone users found that 133 of them developed cancer of the brain or nervous system. prior to this study of cell phone use, the rate of such cancer was found to be 0.0449% for those not using cell phones. complete parts (a) and (b). a. use the sample data to construct a 95% confidence interval estimate of the percentage of cell phone users who develop cancer of the brain or nervous system.

(0.0263%, 0.0370%)

Step-by-step explanation:

Sample size = n = 420,100

Number of users who developed cancer = x = 133

Proportion of users who developed cancer = p =

Proportion of users who didnot develop cancer = q = 1 - p =

Confidence Level = 95%

Z value associated with this confidence level = z = 1.96

The formula to calculate the confidence interval is:

Using the values in above expressions, we get:

and

Thus, the bounds of the confidence interval are:

(0.000263, 0.000370)

This can be expressed in percentages as:

(0.0263%, 0.0370%)

Therefore, a 95% confidence interval estimate of the percentage of cell phone users who develop cancer of the brain or nervous system is (0.0263%, 0.0370%)

18.8 cubic inches.

step-by-step explanation:

volume of a cone = πr²h

r = 1.5 inches

h = 8 inches

pi = 3.14

volume of our cone = × 3.14 × 1.5² × 8 = 18.84 square inches

or equals to 18.8 square inches rounded up to nearest tenth.

answer: 819.89 miles across america

step-by-step explanation: