QUESTION 1

A research rm conducted a survey to determine the mean repair cost on refrigerators. They found that the distribution of repair costs followed the normal distribution with a population standard deviation of $15.50. A random sample of 45 refrigerators had a mean repair cost of $73.50. Round your answer in part (a) to 2 decimal places. (a) What is the critical zvalue that will need to be used to calculate the 95% condence Round your answers in part (b) to 2 decimal places. (b) What is the 95% condence interval? Round your answer in part (c} to 2 decimal place. (c) What is the critical zvalue that will need to be used to calculate the 93% condence Round your answers in part (d) to two decimal places. {d} What is the 98% condence intenral? The Sugar Producers Association wants to estimate the mean yearlyr sugar consumption per individual. A sample of 10 people had a mean yearly consumption to be 25.85 kg and a standard deviation of ?'.40 kg. Assume the sugar per individual is normally distributed. {a} What is the best point estimate of the population mean? :] For part (b), round your answer to 3 decimal plans. {b} What is the critical tvalue that will need to be used to calculate the 90% condence For part (1:), round your answers to 4 decimal places. (c) What is the 90% condence interval? Suppose you have ajar with 20 marbles. 13 marbles are red, and TI" marbles are blue. You draw marbles one at a time from the jar, without replacing them. What is the probability of drawing a red marble, then a red marble, then a blue marble? Round your answer to at least 4 decimals. Cl