Question

1). A survey asked San Diego residents the following question: “If you had been aware that
before Arnold Schwarzenegger ran for Governor, he had fathered a child outside of his
marriage, would you still have voted for him?” Out of the 150 males surveyed who had voted
for Schwarzenegger 84 said they would still vote for him, and out of the 120 females 51 said
they would. Does the data suggest that there is a difference between the proportion of male
and female San Diego residents who would have voted for Schwarzenegger had they known
he had fathered a child outside of his marriage? Test at the 10% level of significance

2). The operations manager of Pirelli Tires wants to see if there are any differences in the quality
of workmanship among the day and night shifts. She randomly selects 400 tires and carefully
inspects them. Each tire is either classified as perfect, satisfactory, or defective, and the shift
that produced it is also recorded. Does the data provide enough evidence to conclude there
are differences in quality among the two shifts? Test at the 5% level of significance.
H0
HA
Critical Value Write the expected frequencies in the table
Test Statistic Decision/Justify
Conclusion: Circle the Correct One
A. Yes, there is enough evidence to conclude there are differences in quality among the 2 shifts.
B. No, there is not enough evidence to show there are differences in quality among the 2 shifts.
Perfect Satisfactory Defective Total
Day 115 130 5 250
Night 53 86 11 150
Total 168 216 16 400

Answer 1

Sample proportions, Male female. P = 0.50 - 0.495 ret los be acolo, Zop= 1.645 to . Pipe Hi pi € B unden Ho, test Statistic es, = - N001) Pacht where pe altar - 84+5) Sith 150+120 P=0.5, Q=1-P=0.5 - Z - 0.56 -0.425 v 2.205 20 we Vos(0.)(150 Hits) Z > 1645, we refect Ho. we can conclude that there is a difference between the propor tion of male and female san welgo residents who would have voted for Schwarzenegger had they known he had fathered a chold outen of his marriage

Z critical value is taken from z table at Alfa= 0.10 for a two Tailed test.