Jon Southam, Teacher at New Technology High School, Numerade Educator

08:46

Intro Stats / AP Statistics

An online order application estimated that the mean amount of time it takes each store to deliver the order is 45 minutes. The manager wants to determine if a new system for processing delivery orders will reduce the mean delivery time. They take a sample of 15 delivery orders and find that their mean delivery time is 48 minutes with a standard deviation of 8 minutes under the new system. Let µ represent the mean delivery time under the new system.

1. Select the most appropriate null and alternative hypotheses.
2. Calculate the test statistic. Round your answer to 3 decimal places (e.g. 2.0155 becomes 2.016)
3. Select the most appropriate p-value:
a) 0.05 < p-value < 0.1
b) 0.1 < p-value < 0.05
c) 0.025 < p-value < 0.5
d) 0.9265
4. Select the most appropriate conclusion:
a) Since the p-value is greater than the significance level, we reject the null hypothesis.
b) Since the p-value is less than the significance level, we reject the null hypothesis.
c) Since the p-value is greater than the significance level, we do not reject the null hypothesis.
d) Since the p-value is less than the significance level, we do not reject the null hypothesis.
5. Select the most appropriate interpretation:
a) The population mean time under the old system is likely not as long as the population mean time under the new system.
b) The population mean time under the new system is likely at least as long as the population mean time under the old system.
c) There is likely no difference between the population mean time under the old and new systems.
d) There is likely a difference between the population mean time under the old and new systems, but we cannot tell a direction (i.e. we cannot tell which one is faster than the other).