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Get Full Access to Elementary Statistics - 12 Edition - Chapter 5.4 - Problem 13bsc
Get Full Access to Elementary Statistics - 12 Edition - Chapter 5.4 - Problem 13bsc

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# Cell Phones and Brain Cancer In a study of 420,095 cell ISBN: 9780321836960 18

## Solution for problem 13BSC Chapter 5.4

Elementary Statistics | 12th Edition

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Problem 13BSC

Problem 13BSC

Cell Phones and Brain Cancer In a study of 420,095 cell phone users in Denmark, it was found that 135 developed cancer of the brain or nervous system. If we assume that the use of cell phones has no effect on developing such cancer, then the probability of a person having such a cancer is 0.000340.

a. Assuming that cell phones have no effect on developing cancer, find the mean and standard deviation for the numbers of people in groups of 420,095 that can be expected to have cancer of the brain or nervous system.

b. Based on the results from part (a), is 135 cases of cancer of the brain or nervous system unusually low or high?

c. What do these results suggest about the publicized concern that cell phones are a health danger because they increase the risk of cancer of the brain or nervous system?

Step-by-Step Solution:

Step 1 of 1

a)

Number of samples n=420095

p=0.000340

r=135

Since it follows binomial distribution,

Then the Mean of the formula is

μ=np

μ =420095* 0.000340

μ =142.8323

μ =142.8 (Rounded to one decimal place)

The formula of the standard deviation is given by

σ= σ = σ = σ = 11.9492149122024

σ =11.95 (Rounded to two decimal places)

b)

We know that μ=142.8323 and σ = 11.9492149122024

Maximum usual values μ + 2σ and Minimum usual values μ-2σ

= ( μ ± 2σ)

= (142.8323±2*11.9492149122024 )

= (142.8323±23.8984298244048 )

= (142.8323-23.8984298244048 , 142.8323+23.8984298244048)

= (118.933870175595 , 166.730729824405)

= (119,167)

Since 135 falls under the above interval, it is not unusual.

c)

The results propose that the publicized concern is not true.

The data does not provide sufficient evidence to reject the hypothesis that the cell phones do not affect the incidence of brain cancer.

Step 2 of 1

##### ISBN: 9780321836960

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