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%)

the correct option is 2.

step-by-step explanation:

according to the given information triangle abc is a right angle triangle with right angle at a. segment ab is 5 and segment ac is 7. point d is on segment bc and angles adb and adc are right angles.

it is given that triangles abd, cad, and cba are similar.

two triangles are similar if their corresponding sides are proportional.

in triangle cba, using pythagoras theorem

                      )

triangle abd and cba are similar,

                            (2)

triangle cad and cba are similar,

                      )

using (1), (2) and (3), we get

hence proved.

therefore option 2 is correct.

answer: 10 turtles

step-by-step explanation: as turtles have four legs so 4.10=40 therefore birds are 4 which sue counted