A sample size must be determined for estimating a population mean given that the confidence level is % and the desired margin of error is . The largest value in the population is thought to be and the smallest value is thought to be . Calculate the sample size required to estimate the population mean using a generously large sample size. (Hint: Use the range/6 option.)

Complete Question

The complete question is shown on the first uploaded image

a

b

c

 The correct option is  D

Step-by-step explanation:

From the question we are told that

    The margin of error is  

     The largest value is  k =  15

     The smallest value is  u = 7

From the question we are told the confidence level is  95% , hence the level of significance is    

=>  

Generally from the normal distribution table the critical value  of   is  

Generally population  standard deviation estimate is mathematically represented as

Here the Range is mathematically represented as

=>    

=>    

=>  

=>  

Generally the sample size is mathematically represented as

=>  

=>  

Generally to obtain a  conservatively small sample size the population standard deviation estimate becomes

=>  

=>  

=>  

Generally the conservatively small sample size is mathematically evaluated as

=>  

=>    

answer: the answer is 35%

70

step-by-step explanation:

2*5=10

4*15=60

60+10=

70