Question Suppose that the number of dollars spent per week on groceries are normally distributed with an unknown mean and standard deviation. A random sample of 18 grocery bills is taken and gives a sample mean of 103 dollars and a sample standard deviation of 10 dollars. The margin of error for a 98% confidence interval estimate for the population mean using the Student's t-distribution is 6.05.  Find a 98% confidence interval estimate for the population mean using the Student's t-distrib...

Question In a recent survey, a random sample of 1,625 people shopping for a new car were asked whether they would pay the sticker price for the car. 926 reported that they would wait for the salesman to make a better offer on the car before purchasing it. What value of z should be used to calculate a confidence interval with a 90% confidence level? Question Suppose the weights of a population of female Siamese cats are normally distributed with an unknown population mean and a popula...

Question Michelle, a student studying music, randomly sampled fellow music majors and asked whether they listen to music while they study. The resulting confidence interval for the proportion of music students who listen to music while studying is (0.09,0.26). What is the margin of error?   Question Suppose we know that a confidence interval for a population proportion is (0.572,0.662), with a sample proportion of p′=0.617. What is the margin of error?     Question...

question 1 Peter has collected data to find that the finishing times for cyclists in a race has a normal distribution. Based on the Empirical Rule, what is the probability that a randomly selected race participant had a finishing time of greater than 171 minutes if the mean is 156 minutes and the standard deviation is 15 minutes? Enter your answer as a percent rounded to 2 decimal places if necessary. Include the percent symbol % in your answer.   QUESTION 2 A softball pitcher h...

Question Two thousand students took an exam. The scores on the exam have an approximate normal distribution with a mean of μ=81 points and a standard deviation of σ=4 points. The middle 50% of the exam scores are between what two values? Use Excel, and round your answers to the nearest integer.   Question A firm’s marketing manager believes that total sales for next year will follow the normal distribution, with a mean of $3.2 million and a standard deviation of $250,000. D...

Question As in the previous problem, a fair coin is flipped 80 times. If X is the number of heads, then the distribution of X can be approximated with a normal distribution, N(40,4.5), where the mean (μ) is 40 and standard deviation (σ) is 4.5. Using this approximation, find the probability of flipping 43, 44, or 45 heads. You may use the portion of the Standard Normal Table below. Round the final answer to two decimal places.   Question A fair coin is flipped 80 times. L...

Question Jamie was told that her reading test score was 1 standard deviation above the mean. If test scores were approximately normal with μ=97 and σ=10, what was Jamie's score? Question Alice was told that her reading test score was 2 standard deviations below the mean. If test scores were approximately normal with μ=84 and σ=8, what was Alice's score?   Question Rosetta averages 148 points per bowling game with a standard deviation of 14 points. Suppose Rosetta's points per bowl...

QUESTION 1 A random sample of house sizes in major city has a sample mean of x¯=1204.9 sq ft and sample standard deviation of s=124.6 sq ft.  Use the Empirical Rule to determine the approximate percentage of house sizes that lie between 955.7 and 1454.1 sq ft. Round your answer to the nearest whole number (percent).   QUESTION 2 Andrea conducted a survey in which she collected data on the percentage of people who like horror films and the percentage of people who like romanti...

Question Use the completed contingency table to find the probability that a citizen exercises, given that they are female. Express your answer as a fraction. Question The following incomplete contingency table shows a random sample of 160 citizens were asked if they exercise. Complete the table.   Question Fill in the following contingency table and find the number of students who both have a cat AND have a dog. Question Fill in the following contingency table and find th...

Question Given that P(A AND B)=0.70 and P(A|B)=0.94, what is P(B)? Round your answer to three decimal places.   Question The probability that a child watches cartoons after school is 0.56. The probability that the child requests a certain toy of a cartoon character given that the child watches cartoons after school is 0.89. What is the probability that a child will request a toy and watch cartoons after school? Give your answer as a percent, rounded to two decimal places if ne...