The 2003 Statistical Abstract of the United States reported the percentage of people years of age and older who smoke. Suppose that a study designed to collect new data on smokers and nonsmokers uses a preliminary estimate of the proportion who smoke of . a. How large a sample should be taken to estimate the proportion of smokers in the population with a margin of error of

Complete Question

The 2003 Statistical Abstract of the United States reported the percentage of people 18 years of age and older who smoke. Suppose that a study designed to collect new data on smokers and non smokers uses a preliminary estimate of the proportion who smoke of 0.30.

a. How large a sample should be taken to estimate the proportion of smokers in the population with a margin of error of 0.02? use 95% confidence.

b. Assume that the study uses your sample size recommendation in part (a) and finds 520 smokers. What is the point estimate of the proportion of smokers in the population?

c. What is the 95% confidence interval for the proportion of smokers in the population?

a

b

c

Step-by-step explanation:

Considering question a

From the question we are told that

    The margin of error is  

     The preliminary estimate of the proportion who smoke is  

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 the sample size is mathematically  represented as  

=>  

=>  

Considering question b

 From the question we are told that

   The number of smokers  is  k =  520  

Generally the  point estimate of the proportion of smokers in the population is mathematically represented as

=>    

Considering  question c

Generally 95% confidence interval is mathematically represented as  

=>  

=>  

x = central angle apc = measure of minor arc ac

the two angles x and 30 add to 180, so x+30 = 180 and x = 180-30 = 150. the measure of minor arc ac is 150 degrees.

what we need to do from here is find the circumference and then multiply it by x/360 since there are 360 degrees in a circle. in this case, x = 150, so x/360 = 150/360 = 15/36 = 5/12. the shortest distance along the curve from a to c is 5/12 of the distance around the entire circle (aka circumference)

c = circumference

c = pi*d

c = pi*24

c = 24pi

now multiply this by 5/12 to get

distance along minor arc ac = (5/12)*(circumference)

distance along minor arc ac = (5/12)*(24pi)

distance along minor arc ac = 10pi

the formula you can use is

l = (x/360)*pi*d

with

l = length of minor arc

x = central angle

d = diameter

which essentially is the steps we took though a bit differently.

1. d.90

2. e. none of these (80)

3. a. 0

4. b. 6

5. e. none of these (10)

6. a. 5