Question

1. I wanted to estimate the population mean number of cups of coffee people drink in a day. I asked a group of 10 friends how many cups of coffee they have in a day. I received the following results: 2, 2, 3, 2, 0, 5, 1, 4, 2, 1. For my population mean, I am choosing a 95% confidence level.

2. I decided to go with option two and go with the car theme because I just bought a Hyundai Elantra. I found that Hyundai sold 175,094 Elantra's in 2019. Across all its models, Hyundai sold 688,771 cars in 2019. I decided to calculate a 90% confidence interval for the population proportion.

3. I would like to study is family members that have been on a sports team within the last year. My numbers I obtained from 10 different families are as followed 1, 3, 0, 2, 1, 4, 0, 2, 2 and 3. I will choose 95% confidence interval for my population mean.

For your response to a classmate (two responses are required, one in each option), solve a classmate’s confidence interval problem using a confidence level not previously used for that specific classmate’s problem. Make sure that you use appropriate terminology to state the problem and explain your solution.

Answer 1

Que.1

95% confidence interval for population mean:

Here

We are 95% confident that mean number of cups of coffee people drink in a day is lie between 1.14 to 3.26

Que.2

90% confidence interval for the population proportion:

Here

We are 90% confident that proportion of Elantra sold by Hyundai in 2019 lies between 0.249 to 0.251.

Que.3

95% confidence interval for population mean:

Here