Question

The claim is that the IQ scores of statistics professors are normally​ distributed, with a mean less than 125. A sample of 19 professors had a mean IQ score of 123 with a standard deviation of 4. Find the value of the test statistic. The value of the test statistic is .....

Answer 1

Solution :

This is the left tailed test .

The null and alternative hypothesis is ,

H0 :   = 125

Ha : < 125

Test statistic = z

= ( - ) / / n

= (123 - 125) / 4 / 19 = -2.179

The value of the test statistic is -2.179