A Gallup poll of 547 adult Americans employed full or part-time, conducted August 13-16, 2007, asked, “How much total in minutes do you spend commuting to and from work on a typical day?” Survey...

Question 1:
According to 2009 Lawyers.com survey, only 35% of adult Americans had a will (The Wall
Street Journal, December 12, 2011). Suppose a recent survey of 250 adult Americans found 100
adults with wills.
a. Specify the competing hypothesis to determine whether the proportion of adult
Americans that have a will differs from the proportion reported for 2009.
b. Calculate the value of the test statistic and the p-value
c. At the 5% significance level, is the proportion different? Explain.
Answer 1:
a. Let p = proportion of adult Americans that have a will (The Wall Street Journal,
December 12, 2011)
po = 0.35
Sample proportion,
100
0.4
250
p  
Hypothesis:
Null Hypothesis: There is no significant difference between the proportion of adult
Americans that have a will and proportion reported for 2009.
That is, Ho: p = po
Alternative Hypothesis: There is difference between the proportion of adult Americans
that have a will and proportion reported for 2009.
That is, Ho: p ≠ po
b. If n*po > 10 and n*(1 – po) ≥ 10 then use the following Z-test statistic.
 1
o
o o
p p
z
p p
n




Here, n*po = (250) × (0.35) = 87.5 > 10
And n*(1 – po) = (250) × (1-.35) =...