Probability and Confidence Intervals Review

1.Nolan flipped his lucky coin 18 times and got 10 heads. Nolan used these numbers to estimate the probability of getting a head with his lucky coin.

What is the estimated probability of Nolan flipping a head with his lucky coin?________

(Write your answer as a decimal rounded to 3 decimal places)

Find the margin of error for Nolan's estimated probability above. ________

(Write your answer as a decimal rounded to 3 decimal places)

Create a confidence interval for the chance of flipping a head with Nolan's lucky coin.

________ to ________ (Write your answer as a decimal rounded to 3 decimal places)

2.Oswald is registering for classes next semester. He uses the Quantitative Reasoning Process to decide between two teachers, Dr. Adams, and Dr. Baldwin. He speaks to 19 friends that previously took the course from Dr. Adams and also speaks to 19 friends that took it from Dr. Baldwin. Eight of his friends said they highly recommend Dr. Adams. Eleven of his friends highly recommend Dr. Baldwin.

Based on Oswald's minimal study, what percent of students "highly recommend" Dr. Adams?

________ % (Round the final percentage to one decimal place)

What percent "highly recommend" Dr.Baldwin?

________ % (Round the final percentage to one decimal place)

To be statistically accurate in his decision, Oswald decides to create a 95% confidence interval for his two percentages. What values does he find for each confidence interval?

Confidence interval for the true proportion that "highly recommend" Dr Adams:

(Enter the low value in the first blank and the high value in the second blank. Round values to one decimal place)

________ % to ________ %

Confidence interval for the true proportion that "highly recommend" Dr. Baldwin:

(Enter the low value in the first blank and the high value in the second blank. Round values to one decimal place)

________ % to ________ %

3.If Kate takes a 25-question multiple choice test and receives a score of 40%, how many questions did she answer correctly? ________

If her teacher used a 95% confidence interval to correctly estimate the true percentage of correct answers that she should have scored on this exam, what possible grades could the teacher reasonably assign to Kate?

Anything from ________ % to ________ %

However, because Kate's teacher must pick only one number to represent her grade, what percentage will the teacher typically assign as the grade? ________ %

4.The table below shows which hand is favored by each person from a sample of 100 people (50 male and 50 female). Use the information in the table to answer the following questions.

Left-Handed

Right-Handed

Male

15

35

Female

10

40

Determine the probability that a randomly selected person from the sample will be female or left-handed.

________ % (Round to the nearest whole percentage)

Compute a 95% confidence interval for the true proportion of the population that is left-handed.

________ % to ________ %

Compute a 95% confidence interval for the true proportion of the population that is right-handed.

________ % to ________ %

1. Nolan flipped his lucky coin 18 times and got 10 heads. Nolan used these numbers to estimate the probability of getting a head with his lucky coin. What is the estimated probability of Nolan flipping a head with his lucky coin? (Write your answer as a decimal rounded to 3 decimal places) Find the margin of error for Nolan's estimated probability above. (Write your answer as a decimal rounded to 3 decimal places) Create a confidence interval for the chance of flipping a head with Nolan's lucky coin. to (Write your answer as a decimal rounded to 3 decimal places) 2. Oswald is registering for classes next semester. He uses the Quantitative Reasoning Process to decide between two teachers, Dr. Adams, and Dr. Baldwin. He speaks to 19 friends that previously took the course from Dr. Adams and also speaks to 19 friends that took it from Dr. Baldwin. Eight of his friends said they highly recommend Dr. Adams. Eleven of his friends highly recommend Dr. Baldwin. Based on Oswald's minimal study, what percent of students "highly recommend" Dr. Adams? % (Round the final perc to one decimal place) What percent "highly recommend" Dr.Baldwin? % (Round the final percentage to one decimal place) To be statistically accurate in his decision, Oswald decides to create a 95% confidence interval for his two percentages. What values does he find for each confidence interval? Confidence interval for the true proportion that "highly recommend" Dr Adams: (Enter the low value in the first blank and the high value in the second blank. Round values to one decimal place) % to % Confidence interval for the true proportion that "highly recommend" Dr. Baldwin: (Enter the low value in the first blank and the high value in the second blank. Round values to one decimal place) % to % 3. If Kate takes a 25-question multiple choice test and receives a score of 40%, how many questions did she answer correctly? If her teacher used a 95% confidence interval to correctly estimate the true percentage of correct answers that she should have scored on this exam, what possible grades could the teacher reasonably assign to Kate? Anything from % to % However, because Kate's teacher must pick only one number to represent her grade, what percentage will the teacher typically assign as the grade? % 4. The table below shows which hand is favored by each person from a sample of 100 people (50 male and 50 female). Use the information in the table to answer the following questions. Left-Handed Right-Handed Male 15 35 Female 10 40 Determine the probability that a randomly selected person from the sample will be female or left-handed. % (Round to the nearest whole percentage) Compute a 95% confidence interval for the true proportion of the population that is left-handed. % to % Compute a 95% confidence interval for the true proportion of the population that is right-handed. % to %