Astudy of 420 comma 000 cell phone users found that 134 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 0.0438% for those not using cell phones. use the sample data to construct a 90% confidence interval estimate of the percentage of cell phone users who develop cancer of the brain or nervous system.

(0.00306,0.00334)

Step-by-step explanation:

Given : Sample size : n= 420000

The number of users developed cancer of the brain or nervous system =134

Then , the proportion of users developed cancer of the brain or nervous system :

Significance level :

Critical value :

The confidence interval for population proportion is given by :-

Hence, the 90% confidence interval estimate of the percentage of cell phone users who develop cancer of the brain or nervous system is (0.00306,0.00334).

a) 0.25x times 3. (could be wrong on equation.)

b) 2.25 pound of dark chocolate. (can i eat all the chocolate? plz? anyway, again, could be wrong, but i hope im right. all the chocolate together should be 5.25 pounds)

have a good day!