Question

The claim is that the white blood cell counts of adult females are normally? distributed, with a standard deviation equal to

2.17

.

A random sample of

45

adult females has white blood cell counts with a mean of

7.67

and a standard deviation of

3.83

.

Find the value of the test statistic.

The test statistic is

nothing

.

?(Round to three decimal places as? needed.)

Answer 1

Given that,

Sample size (n) = 45

Sample mean $(\bar X)$ = 7.67

Sample standard deviation (S) = 3.83

Null and alternative hypotheses are,

$H_0: \sigma = 2.17$

$H_1: \sigma \neq 2.17$

Test statistic is,

$\chi^2 = \frac {(n-1)S^2}{\sigma^2}$

  $= \frac {(45-1)(3.83)^2}{(2.17)^2}$

$\chi^2 = 137.066$

Hence,

The test statistic is 137.066