Suppose the last stage in an automated assembly-line process is a quality inspection, which must still be done by humans. The target for inspection speed is 30 seconds per item. The company's quality control officer takes a random sample of 35 inspection times, and finds a mean of 31.5 seconds, with standard deviation of 5.5 seconds.In this problem, you’ll test whether there’s evidence that the mean inspection time is greater than
30 seconds, using a 10% significance level.
A. Write your hypotheses, making sure to use correct statistical notation
B. Do the t-test using the P-value approach, making sure to show the numbers you compare to come to your conclusion. [You can use StatKey or other technology to get the P-value.]
C. State the results of your hypothesis test in a complete sentence that refers to the details of this real-world example