Question

In the early 1900s, nutritionists believed people who ate no meat had lower blood pressure. In the population of all Americans, the average systolic blood pressure of 121.2 mmHg. You decide to test this by selecting 10 vegetarians; the sample had an average systolic blood pressure of 116.3 mmHg, with a standard deviation of 3.2.

What is the observed test statistic?

Answer 1

Solution,

The null and alternative hypothesis is ,

H₀ :   = 121.2

H_a : < 121.2

= 116.3

s = 3.2

n = 10

Test statistic = t =

= ( - ) / s / n

= (116.3 - 121.2) / 3.2 / 10

Test statistic = t = -4.84