Understanding Basic Statistics 6th Edition by Charles Henry Brase,Corrinne Pellillo Brase

Exercise 95

What is the level of significance State the null and alternate hypothesis.
(b) Check Requirements What sampling distribution will you use What assumptions are you making What is the value of the sample test statistic
(c) Find (or estimate) the P -value. Sketch the sampling distribution and show the area corresponding to the P -value.
(d) Based on your answer in parts (a) to (c), will you reject or fail to reject the null hypothesis Are the data statistically significant at level
(e) Interpret your conclusion in the context of the application. Note: For degrees of freedom d.f. not in the Student's t table, use the closest d.f. that smaller. In some situations, this choice of d.f. may increase the P -value by a small amount and therefore produce a slightly more "conservative" answer. Answers may vary due to rounding.
Toys: Electric Trains The Toylot Company makes an electric train with a motor that it claims will draw an average of only 0.8 ampere (A) under a normal load. A sample of nine motors was tested, and it was found that the mean current was
= 1.4A, with a sample standard deviation of s = 0.41A. Do the data indicate that the Toylot claim of 0.8 A is too low (Use a 1% level of significance.)