The U.S. National Center for Health Statistics records information on each new b

Question

The U.S. National Center for Health Statistics records information on each new baby born, such as time and date of births, weight, and sex. On bit of information available from these data is the day of the week on which each baby was born. Under the proportional model, we would expect that babies should be born at the same frequency on all seven days of the week. But is this true? The following table lists the number of babies born on each day of the week in a random sample of 350 births. Day Number of Births Sunday 33 Monday 41 Tuesday 63 Wednesday 63 Thursday 47 Friday 56 Saturday 47 a. Write a null and alternative hypothesis to test the claim that the proportion of births should be 1/7 for each day of the week. b. Test this hypothesis giving the test statistic and p-value and conclusion about this test. (You can use R to get the values).

Explanation / Answer

a) H0: The proportion of births is uniformly distributed over the week .

H1: The proportion of birth is not uniformly distributed over the week.

b) This accounts for Good ness of fit test for 1 variable.

Compute test statistic.

The p value at df=6 is 0.018.

The p value is less than alpha=0.05. Reject null hypothesis to cocnlude that proportion of birth is not uniformly distributed over the week.

Observed Expected (Observed-Expected)^2/Expected Sunday 33 50[350*0.142857] 5.78 Monday 41 50 1.62 Tuesday 63 50 3.38 Wed 63 50 3.38 Thurs 47 50 0.18 Fri 56 50 0.72 Sat 47 50 0.18 X^2=15.24

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.