Question

1.Which of the following scenarios would it be appropriate to use a normal approximation for the sampling distribution of the sample proportion?

Select one:

a.) A researcher wishes to find the probability that more than 60% of a sample of undergraduate students from UNC will be female. She samples the first 42 students that walk into the gym on Monday morning. The population proportion of undergraduate females at UNC is known to be 60.1%.

b.)A researcher wishes to find the probability that less than 5% of a sample of undergraduate students from Appalachian State University will be between the ages of 25 and 34. He randomly samples 50 undergraduate students from the student database. The proportion of undergraduates between the ages of 25 and 34 is 5.3%.

c.)A grad student at NC state wants to know how likely it is that a group of students would be made up of more than 27% graduate students. She will randomly select 38 students and ask them if they are a graduate student or an undergraduate student. The population proportion of grad students at NC state is 26.6%.

d.)A full-time student at Fayetteville State University wants to know how likely it is that a group of students would be made up of less than 70% full-time students. She will ask 30 people that she sees parking in the parking deck if they are full-time or part-time. The population of full-time students at Fayetteville State is known to be 72%.

2. In the general population in the US, identical twins occur at a rate of 30 per 1,000 live births. A survey records 10,000 births during Jan 2018 to Jan 2019 and found 400 twins in total. Which of the following are true?

Select one or more:

The proportion of twin births during Jan 2018 to Jan 2019 is .03.

The proportion of twin births during Jan 2018 to Jan 2019 is .04.

The probability of twin births among the general population is .03.

The probability of twin births among the general population is .04.

Pr(observing a sample proportion of twin births from a random sample of 10,000 live births <= 0.04) = 0.03.

Pr(observing a sample proportion of twin births from a random sample of 10,000 live births <= 0.04) = 0.5.

Pr(observing a sample proportion of twin births from a random sample of 10,000 live births <= 0.03) = 0.04.

Pr(observing a sample proportion of twin births from a random sample of 10,000 live births <= 0.03) = 0.5.

Answer 1