A drug company is considering marketing a new local anesthetic. The effective time of the anesthetic the drug company is currently producing has a normal distribution with an average of 7.4 minutes. The chemistry of the new anesthetic is such that the effective time should be normal with the same standard deviation, but the mean effective time may be lower. If it is lower, the drug company will market the new anesthetic; otherwise, they will continue to produce the older one. A hypothesis test will be done to help make the decision.

A sample of size 36 results in a sample mean of 7.1 and a sample std deviation of 1.2.

Complete the 5 step hypothesis test at significance level 0.10; make and support your decision.

Step 1: Null and alternate hypothesis (H0 and HA):

Step 2: Level of Significance:

Step 3: Statistics Test/Statistics to be used:

Step 4: Rejection Criteria (draw normal curve; identify rejection area; state critical t value)

Step 5: Calculate t statistic; determine p-value; make decision about H0