Question

1.The delivery times for a courier company are uniformly distributed between 2 day and 4 days. What is the probability that a package will be delivered between 2.5 days and 3 days? Select one: a. 1.0 b. 0.75 c. 0.25 d. 0.5 e. 0.33

2..

In crash tests of 20 Honda Odyssey minivans, collision repair costs are considered. The sample data has a distribution that is roughly bell shaped, with a mean of $1866 and a standard deviation of $832. What is the 99% confidence interval for the mean repair costs of all such minivans?

Select one:

a.
(1394, 2338)    

b. (1337, 2395)  

c. (1334, 2398)

d. (1387, 2345)

e. (1396, 2336)  

Independent random samples of size n₁ = 20 and n₂ = 15 are drawn from two normal populations with equal unknown variance σ². The respective sample standard deviations are s₁ = 3.0 and s₂ = 2.8. The estimate of the common population variance σ² is:

Select one:

a. 8.420

b. 2.821

c. 8.508

d. 2.900

e. 5.900

In testing H0:μ=77 versus Ha:μ≠77 for some population, a random sample of 17 observations from a normally distributed population with unknown standard deviation yielded a test statistic of 2.638.   The  p-value for this test is

Select one:

a. between 0.01 and 0.02

b. impossible to determine based on the given information.

c. 0.0082

d. 0.0041

e. between 0.005 and 0.010

Answer 1