Question

23 6 16 73 In a recent poll, a random sample of adults in some country (18 years and older) was asked, "When you see an ad emphasizing that a product is "Made in our country," are you more likely to buy it, less likely to buy it, or neither more nor less likely to buy it?" The results of the survey, by age group, are presented in the following contingency table. Complete parts (a) through (c). Purchase likelihood 18-34 35-44 45-54 55+ Total More likely 228 385 386 405 1404 Less likely 28 Neither more nor less likely 282 218 170 119 789 Total 533 609 584 540 2266 (a) What is the probability that a randomly selected individual is 35 to 44 years of age, given the individual is neither more nor less likely to buy a product emphasized as "Made in our country"? The probability is approximately (Round to three decimal places as needed.) (b) What is the probability that a randomly selected individual is neither more nor less likely to buy a product emphasized as "Made in our country," given the individual is 35 to 44 years of age? The probability is approximately (Round to three decimal places as needed.) (c) Are 18-to 34-year-olds more likely to buy a product emphasized as "Made in our country" than individuals in general? Yes, more likely No, less likely

Answer 1

1)

a)

P(35-44 |neither more or less likely) =218/789 =0.276

b)

P(neither more or less likely |35-44)=218/609 =0.358

c)

no, less likely

2)

sample mean 'x̄=		66.000
sample size    n=		37
std deviation s=		5.0000
std error ='sx=s/√n=5/√37=		0.8220

for 90% CI; and 36 df, value of t=		1.688		from excel: t.inv(0.95,36)
margin of error E=t*std error    =		1.388
lower bound=sample mean-E =		64.612
Upper bound=sample mean+E =		67.388
from above 90% confidence interval for population mean =(64.6 <μ< 67.4)

option C is correct : ......is between 64.6 and 67.4 months