Confidence Interval for a Proportion

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Which of the following is true for a 90% confidence interval for the population proportion.

It tells us that the population proportion is approximately 0.90.

It tells us that 90% of all proportions are within the interval.

It tells us that 90% of all such confidence intervals will contain p^\hat{p}p^​.

It tells us that 90% of all such intervals contain the true population proportion ppp.

I don't know

Confidence Interval

You are given an 99% confidence interval for the proportion of homeowners that still have a home phone →\rightarrow→ (0.35, 0.49)
1. What is an estimate for the proportion of homeowners having a home phone?
2. What is the standard error of the sample proportion of homeowners owing a home phone?

Confidence Interval for a Proportion

A random sample of 1000 people in Calgary were asked if they are satisfied with their mobile carriers: “YES or NO?” Results: 535 people said YES.

Confidence Interval for a Proportion

A random sample of 1000 people in Calgary were asked if they are satisfied with their mobile carriers: “YES or NO?” Results: 535 people said YES.

Confidence Interval for a Proportion

Based on a random sample of 200 households, 70 of them have at least one pet. Construct a 95% confidence interval for the households that has pets. 

Confidence Interval for a Proportion

Parts (i) to (iv) are based on the following information:
In 2006, it was reported that only 40% of students at the university ask questions in lectures. It is believed that this percentage has changed. You randomly sampled 80 students and asked them "Have you ever asked a question in a lecture?" Twenty-four of them responded "Yes". There are 20,386 students at the university.
(iii) What is the p-value?

Population sampling

There are 600 Sephora locations in the United States. Christine randomly selected 40 stores, and then she randomly selected 100 customers from each of those stores. Less than 1% of her sample identified as heterosexual males. Based on her sample, the average spending at Sephora is $45. In addition, 340 customers in her sample revealed that they have VIB Rouge status, which the highest tier status that is reached when a customer spends $1,000 in a calendar year.
Which of the following is/are true? (Check all that applies.)

Confidence Interval for a Proportion

Based on a sample, the average time it takes a customer to eat a burger is 20 minutes with a standard deviation of 8 minutes. Furthermore, 27 customers in the sample ordered the vegetarian burger. 
We are 95% confident that between 23.1% and 43.6% of all customers order the vegetarian burger. Construct a 95% confidence interval for the average time it takes all customers to eat a burger.

Confidence intervals

Based on a sample of 800 children in Twin Pines, 82% of them are vaccinated. Interpret a 95% confidence interval [0.788, 0.852]\left[0.788,\ 0.852\right][0.788, 0.852] in plain English.

Confidence Interval

You are given an 99% confidence interval for the proportion of homeowners that still have a home phone →\rightarrow→ (0.35, 0.49)
1. What is an estimate for the proportion of homeowners having a home phone?
2. What is the standard error of the sample proportion of homeowners owing a home phone?

Confidence Interval for a Proportion

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Confidence Interval for a Proportion

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