When conducting a hypothesis test for the population mean when sigma is known and the sample size is 30 or more, the test statistic follows the ___________________ ____________.
A) Student's t-distribution
B) binomial distribution
C) normal distribution
D) exponential distribution
Question 2
Suppose the average tread-life of a certain brand of tire is 42,000 miles and that this mileage follows the exponential probability distribution.
What is the probability that a randomly selected tire will have a tread-life between 30,000 and 50,000 miles?A) 0.1854
B) 0.2719
C) 0.5105
D) 0.6959
