Question

A normal birth weight is considered to be 3000 g or higher. Do the data provide any evidence that the mean weight at birth of infants born to smoking mothers is less than 3000 g? Carry out the appropriate test with StatCrunch and paste the output into your report. State the null and alternative hypotheses, specify the distribution of the test statistic under the null hypothesis, report the value of the test statistic, and the p-value of the test. Answer the above question.

One sample T hypothesis test:
Where: SMOKING="HS" or SMOKING="MS"
μ : Mean of variable
H₀ : μ = 3000
H_A : μ < 3000

Hypothesis test results:

Variable	Sample Mean	Std. Err.	DF	T-Stat	P-value
WEIGHT	2850.7091	45.816753	54	-3.2584349	0.001

Answer 1

Solution :

From the given Statcrunch output ,

Null and alternative hypothesis are :

H₀ : μ = 3000
H_A : μ < 3000

Test statistics = -3.258

P-value = 0.001