REMEMBER WHEN DOING THE ZTEST OR DOING AN A TTEST YOU MUST C

REMEMBER: WHEN DOING THE Z-TEST OR DOING AN A T-TEST. YOU MUST CONSIDER THE MAIN-CRITERIA AND YOU MUST CONSIDER THE SIZE OF THE SAMPLE. WHEN THE SAMPLE SIZE TURNS OUT SMALL (<30) PERFORM A T-TEST, IF THE SAMPLE-SIZE IS LARGER (>= 30) PERFORM A Z-TEST.   SIMILAR WITH TWO-SAMPLE TESTS.

NUMBER 1

Mention the of test tha shoud be used (is it one-tail, two-tail), then u must set up the null and alternate-hypothesis.

Consider critical value is = CV (like the number 1.96). REMEMBER EACH H0, So, mention the acceptance-range.

NUMBER 1

(A) A SHOP that makes cookies has no less than 70%chocolate per cookie.

(b) A STORE claims that profit daily is is at most around $2000.

(c) A scientis has an preservative to increase the life of a battery. Menan lifetime of this battery with the preservative/additive would be greater then 36 months.

Solution

A) H0: Proportion of chocolate = 70%

Ha: Proportion of chocolate >70%

One tailed test.

B) H0: profit is 2000

Ha: profit <2000

One tailed test.

c) H0: Mean life time = 36 months

Ha: Mean life time >36 months

One tailed