Question

In a study published in 2007 by the NCBI and National Institutes of Health (NIH) under their OpenMed initiative, researchers wanted to determine if there were "differences between ethnic groups with respect to fetal growth." In particular, were infants of European descent heavier at birth than infants of Chinese descent?
a) What hypotheses are they testing?

1. H0: μEuro - μChinese = 0 vs. Ha: μEuro - μChinese > 0

2. H0: pEuro - pChinese = 0 vs. Ha: pEuro - pChinese ≠ 0

3. H0: μD = 0 vs. Ha: μD > 0



b) The researchers reported for their test a p-value of 0.001. What should they conclude at α = .05?

1.Newborn European infants weigh more, on average, than newborn Chinese infants.

2.There is not enough evidence to conclude that newborn European infants weigh more, on average, than newborn Chinese infants.

3.Newborn European infants and newborn Chinese infants do not have significantly different weights.

4. Ethnicity and weight at birth are independent.

Answer 1

Answer:

a) H0: μEuro - μChinese = 0 vs. Ha: μEuro - μChinese > 0

b) Newborn European infants weigh more, on average, than newborn Chinese infants.

Step-by-step explanation:

Null hypothesis would be: infants of European descent has the same weight at birth as Chinese infants. μEuro = μChinese or μEuro - μChinese = 0

And the alternative hypothesis would be: infants of European descent heavier at birth than infants of Chinese descent. μEuro > μChinese or μEuro - μChinese > 0.

Because in particular infants of the European infants are considered heavier. If not,  the alternative hypothesis would be μEuro ≠ μChinese

or μEuro - μChinese ≠ 0.

test a p-value of 0.001 is significant at α = .05, therefore null hypothesis is rejected in favor of alternative hypothesis Ha: μEuro - μChinese > 0, or Newborn European infants weigh more, on average, than newborn Chinese infants.