In a survey, 1864 our of 2246 randomly selected adults in the
US said that texting while driving should be illegal. Consider a
hypothesis test that uses a .05 significance level to test the
claim that more than 80% of adults believe that texting while
driving should be illegal.
In a presidential election 308 out of 611 voters surveyed said
that they voted for the candidate who won. Use a .01
significance level to test the claim that among all voters, the
percentage who believe that they voted for the winning
candidate is equal to 43% which is the actual percentage of
votes for the winning candidate. What does the result
suggenst about voter perceptions?
#12
Find and interpret the p-value for a left tailed test
with n=11 and test statistic t=-3.518
#10
Find and interpret the p-value for a two tailed test
with n=15 and test statistic t=1.495
Researchers collected a simple random sample of the times that
81 college students required to earn their bachelor’s degrees.
The sample has a mean of 4.8 yrs. and a standard deviation
of 2.2 years. Use a .05 significance level to test the claim that
the mean time for all college students is greater than 4.5
years.
Tests were conducted with crashes of new cars traveling at 6
mph. The total cost of the damage was found. Results are
listed for a SRS of tested cars. Use a .05 significance level to
test the claim that when tested under the same standard
conditions, the damage costs for the population of cars has a
mean of $5,000. The costs appear to be normally distributed.
$7448 $4911 $9051 $6374 $4277
A SRS of 40 recorded speeds obtained from cars traveling in a
65 mph speed zone had a mean of 68.4 mph with a standard
deviation of 5.7 mph. Use a .05 significance level to test the
claim that the mean speed of all cars is greater than the
posted speed limit of 65 mph.