A study is performed in a large southern town to determine whether the average weekly grocery bill per 4-person family is significantly different from the national average. A random sample of the weekly grocery bills of four-person families in this town is given in the file attached.(a) Assume that the national average weekly grocery bill […]
Case 7.4 Maximart Sales The inventory manager of Maximart Sales wants to establish optimum ordering policies. Weekly demand for a particular item follows a normal distribution with a mean of 300 units and a standard deviation of 70 units. The supplier will sell Maximart up to 999 units in an order at a price of $100/unit. […]
In the following observational studies, describe changes that could be made to the data collection process that would result in an experiment rather than an observation study. What suggestions about unseen biases or lurking variables that my be present in the studies as they are describe here. a. In a sample of 50 members of a […]
Consider the following reduction ad absurdum proof in propositional logic. The justification lines (to the right) are missing. Fill in the blanks.
A multiple-choice examination consists of 80 questions, each having possible choices a, b, c, and d. Approximate the probability that a student will get at most 20 answers correct if he randomly guesses at each answer. (Note that, if he randomly guesses at each answer, then the probability that he gets any one answer correct is 0.25) Use the normal […]
A brokerage survey reports that 40% of all individual investors have used a discount broker (one that does not charge the full commission). If a random sample of 135 individual investors is taken, approximate the probability that at least 56 have used a discount broker. Use the normal approximation to the binomial with a correction for continuity.
(Problem 1) TRUE or FALSE. Explain your answer for full credit. (2 points each, 10 points total) (a) In a normal distribution, 68% of the area under the curve is within one standard deviation of the mean. (b) Given that a normal distribution has a mean of 50 and standard deviation of 5. The median is also 50. […]
based on the healthy people 2020 do you believe that the US is on course or improving the health of US AS A WHOLE
If 90% of all people between the ages of 30 and 50 drive a car, and assuming a sample of 20 people in that age group:a)What are the mean and standard deviation of the number of people who drive a car in this age group?b)What is the probability that exactly 20 people drive a car?
For which of these variables the median is a better measure of central tendency (average) than the mean: · Individual income in a country · The weight of 5-year old boys · Apartment rental prices in New York · Customer satisfaction · Earnings of S&P500 companies · Age of employees at a large company · Final grades of 25 students in a […]
