Ashford University BUS 308 Week 4 Quiz

1. Question : The manager of the quality department for a tire manufacturing company wants to study the average tensile strength of rubber used in making a certain brand of radial tire. The population is normally distributed and the population standard deviation is known. She uses a Z test to test the null hypothesis that the mean tensile strength is less than or equal to 800 pounds per square inch. The calculated Z test Statistic is a positive value that leads to a p-value of .067 for the test. If the significance level is .10, the null hypothesis would be rejected. Student Answer: True False 2. Question : For the chi-square goodness of fit test, the rejection point X2a is in Student Answer: the left tail of a chi-square curve. both the left and right tails of a chi-square curve. the right tail of the appropriate F curve. the right tail of a chi-square curve. 3. Question : Consider using p-value to test H0 versus Ha by setting ? equal to .10. We reject H0 at level ? of significance if and only if the p-value is: Student Answer: Greater than ?/2 Greater than ? Less than ? None of the above 4. Question : Type II error is defined as the probability of ______ H0 , when it should _____ Student Answer: failing to reject, be rejected. failing to reject, not be rejected. rejecting, not be rejected. rejecting, be rejected. 5. Question : The X2 statistic is used to test whether the assumption of normality is reasonable for a given population distribution. The sample consists of 5000 observations and is divided into 6 categories (intervals). The degrees of freedom for the chi-square statistic is: Student Answer: 4999 6 5 4 3 6. Question : For a hypothesis test about a population mean or proportion, if the level of significance is less than the p-value, the null hypothesis is rejected. Student Answer: True False 7. Question : When carrying out a sample test (with ó known) of H0: µ = 10 vs. Ha: µ > 10 by using a rejection point, we reject Ho at level of significance a if and only if the calculated test statistic is Student Answer: less than Za less than – Za greater than Za/2 greater than Za less than the p value. 8. Question : The X2 statistic from a contingency table with 6 rows and five columns will have _____ degrees of freedom. Student Answer: 30 24 5 20 25 9. Question : Homogeneity is a test of the null hypothesis that all multinomial probabilities are equal Student Answer: True False 10. Question : When using the chi-square goodness of fit test with multinomial probabilities, the rejection of the null hypothesis indicates that at least one of the multinomial probabilities is not equal to the value stated in the null hypothesis. Student Answer: True False