Question

3) In a study of effects of prenatal cocaine use on infants, the following sample data were obtained for weights at birth: n= 190, x(bar)= 2700 g, s= 645 g. Use 5% level of significance to test the claim that the weights of babies born to cocaine users have a mean that is less than mean of 3103 g for babies born to mothers who do not use cocaine. (Please label answers (a), (b), (c) etc. points will be deducted if the answers are not labled. ) Is this a one tailed or a two tailed test? Write the Null Hypothesis in symbols: Write the Null Hypothesis in words: Write the Alternate Hypothesis in symbols: Write the Alternate Hypothesis in words: f.Write the decision rule. No need for the bell curve—just write the rule g.Calculate “Z” h.Write the decision regarding the Null Hypothesis i.Write your conclusion j. Find the p-value.

Answer 1

It is one tailed test

To Test :-

H0 :-  

H1 :-  

Test Statistic :-


t = -8.6124

Test Criteria :-
Reject null hypothesis if


Result :- Reject null hypothesis

Decision based on P value
P - value = P ( t > 8.6124 ) = 0
Reject null hypothesis if P value < level of significance
P - value = 0 < 0.05 ,hence we reject null hypothesis
Conclusion :- Reject null hypothesis

There is sufficient evidence to support the claim that mean that is less than mean of 3103 g for babies born to mothers who do not use cocaine.