Question

part c

Hon Score: 0.64 of 1 pt 1 of 4 (3 complete) HW Score: 63.13%, 2.53 of 4 pts 29.1.25-T Question Help A survey of 2314 adults in a certain large country aged 18 and older conducted by a reputable polling organization found that 422 have donated blood in the past two years. Complete parts (a) through (c) below. (a) Obtain a point estimate for the population proportion of adults in the country aged 18 and older who have donated blood in the past two years. p = 0.182 (Round to three decimal places as needed.) (b) Verily that the requirements for constructing a confidence interval about p are satisfied. The sample can be assumed to be a simple random sample, the value of np(1-) is 345.041, which is greater than or equal to 10, and the sample size can be assumed to be less than or equal to 5% of the population size. (Round to three decimal places as needed.) (c) Construct and interpret a 90% confidence interval for the population proportion of adults in the country who have donated blood in the past two years. Select (Type integers or decimals rounded to three decimal places as needed. Use ascending order.) A We are confident the proportion of adults in the country aged 18 and older who have donated blood in the past two years is between and I OB. There is a chance the proportion of adults in the country aged 18 and older who have donated blood in the past two years is between and 50 w SE () Click to select and enter your answer(s) and then click Check Answer. Clear All Check Answer P All parts showing Communication Tools dtv 4 R 29

Answer 1

c)

Number of Items of Interest,   x =   422      
Sample Size,   n =    2314      
Sample Proportion ,    p̂ = x/n =    0.1824      
              
Level of Significance,   α =    0.1      
z -value =   Zα/2 =    1.645   [excel formula =NORMSINV(α/2)]  
Standard Error ,    SE = √[p̂(1-p̂)/n] =    0.0080      
margin of error , E = Z*SE =    1.645*0.008=   0.0132      
              
Confidence Interval is              
Interval Lower Limit = p̂ - E =    0.1824-0.0132=   0.1692      
Interval Upper Limit = p̂ + E =   0.1824+0.0132=   0.1956      
              
option A)
90% , ( between 0.169 and  0.196   )