Question

In the general population the chances of having twins is 33 in 1,000. It is rumored that inhabitants of the town of Gemini are much more more likely to give birth to twins than people who live elsewhere. Based on the sample of hospital data below, at the 5% significance level, is there evidence to support the rumor of a heightened likelihood of twin births in Gemini compared to elsewhere?

Town of Gemini Pregnancy Study
Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton
Singleton	Singleton	Singleton	Singleton	Twin	Singleton	Singleton	Singleton	Singleton
Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton
Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Twin	Singleton	Singleton
Singleton	Twin	Singleton	Singleton	Singleton	Singleton	Twin	Singleton	Singleton
Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Twin	Twin	Twin
Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton
Singleton	Singleton	Singleton	Singleton	Twin	Singleton	Singleton	Singleton	Singleton
Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton
Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Twin	Singleton	Singleton
Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton
Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton
Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton
Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton
Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton	Singleton

BLANK #1: Is this a question involving mean or proportion? ***ANSWER "MEAN" OR "PROPORTION" (WITHOUT THE QUOTATION MARKS)***

BLANK #2: Which type of distribution should be used to calculate the probability for this question? ***ANSWER "NORMAL", "T", OR "BINOMIAL" (WITHOUT THE QUOTATION MARKS)***

BLANK #3: Which of the following options are the appropriate hypotheses for this question: ***ANSWER WITH THE CORRECT LETTER, WITHOUT ANY QUOTATION MARKS OR BRACKETS***

A) H₀: μ = 33/1,000 H₁: μ > 33/1,000

B) H₀: μ = 33/1,000 H₁: μ < 33/1,000

C) H₀: μ = 33/1,000 H₁: μ ≠ 33/1,000

D) H₀: p = 33/1,000 H₁: p > 33/1,000

E) H₀: p = 33/1,000 H₁: p < 33/1,000

F) H₀: p = 33/1,000 H₁: p ≠  33/1,000

BLANK #4: What is the p-value of this sample? ***ANSWER TO 4 DECIMALS, BE SURE TO INCLUDE LEADING ZERO, EXAMPLE "0.1234"...NOT ".1234"***

BLANK#5: At the 5% significance level, is there evidence to support the rumor of a heightened likelihood of twin births in Gemini compared to elsewhere? ***ANSWER "YES" OR "NO" (WITHOUT THE QUOTATION MARKS)***

Answer 1

PROPORTION is involved.

NORMAL distribution should be used to calculate the probability.

D) H₀: p = 33/1,000 H₁: p > 33/1,000

p-value=0.027

Since p-value<0.05, at the 5% significance level, there is enough evidence to support the rumor of a heightened likelihood of twin births in Gemini compared to elsewhere.

Test and CI for One Proportion

Test of p = 0.033 vs p > 0.033

95%
Lower
Sample X N Sample p Bound Z-Value P-Value
1 7 105 0.066667 0.026626 1.93 0.027