Question

In a recent study, the fibre content (in grams) of 10 randomly selected samples of granola bars are found to have a sample mean of 4.43 grams and a sample standard deviation of 0.68 grams.

Suppose that fibre content measurements are normally distributed among the population of all granola bars.

We wish to test the research hypothesis that the true mean fibre content of granola bars is less than 5 grams. Give the p-value for the appropriate hypothesis test within the accuracy of your tables.

Select one:

a. p-val = 0.0080

b. 0.0075 < p-val < 0.01

c. 0.015 < p-val < 0.02

d. 0.02 < p-val < 0.03

e. 0.01 < p-val < 0.015

f. p-val = 0.0040

Answer 1

This is the left tailed test .

The null and alternative hypothesis is

H₀ : = 5

H_a : < 5

Test statistic = t

= ( - ) / s / n

= (4.43 - 5) / 0.68 / 10

= -2.65

Test statistic = -2.65

df = 9

P-value = 0.0132

e. 0.01 < p-val < 0.015