When 12 bolts are tested for hardness, their indexes have a ...

[Medesa]

When 12 bolts are tested for hardness, their indexes have a standard deviation of 41.7. Test the claim that the standard deviation of the hardness indexes for all such bolts is greater than 30.0. Use a 0.025 level of significance.
 
  What will be an ideal response?

Question 2

Focus groups of 11 people are randomly selected to discuss products of the Yummy Company. It is determined that the mean number (per group) who recognize the Yummy brand name is 8.3, and the standard deviation is 0.88.
 
  Would it be unusual to randomly select 11 people and find that fewer than 5 recognize the Yummy brand name?
  A) Yes B) No

[tdewitt]

Answer to Question 1

Test statistic: X2 = 21.253. Critical value: X2 = 21.920. Fail to reject the null hypothesis. There is not sufficient evidence to support the claim that the standard deviation is greater than 30.0.

Answer to Question 2

A

[Medesa]

TYSM

[kthug]

Gracias!