Stats Help for College-level Students

Stats Tests - ANOVA; Correlation; Regression.

1. A chain of electronic stores is planning to expand the number of stores that it operates. Management believes that there is a relationship between the number of households in a store’s market area and its level sales volume. Management wants to verify its belief that there is a relationship between the two factors before ma ...continues

Sample size

A random sample of 41 basketball players from The Official NBA Basketball Encyclopedia gave the sample standard deviation for player height as s = 3.32 inches. How many more players from this encyclopedia should be included in the sample to be 95% sure that the sample mean is within 0.75 inches of the population mean of all play ...continues

Confidence intervals for one population mean when S.D. is unknown /t-curve

For a t-curve with df = 8, find each t-value and illustrate your results graphically. a.The t-value having area 0.05 to its right. b. t 0.10 c.The t-value having area 0.01 to its left (hint: A t-curve is symmetric about 0.) d.The two t-values that divide the area under the curve into a middle 0.95 area and two outsid ...continues

Probability, normal distribution

An airline company knows that over the long run, only 90% of passengers who reserve seats show up for their flight. On a flight with 300 seats, the airline accepts 324 reservations. Assume the passengers show up independently. 1. Give the upper bound on the probability that the flight will be overbooked (more than 300 peop ...continues

40 MULTIPLE CHOICE QUESTIONS

MULTIPLE CHOICE QUESTIONS In the following multiple choice questions, circle the correct answer. 1. A numerical value used as a summary measure for a sample, such as sample mean, is known as a a. population parameter b. sample parameter c. sample statistic d. population mean e. None of the above answers is cor ...continues

Simulation using random numbers-airline reservation

An airline is trying to determine the number of operators needed for the different areas of their reservation system. The reservation system first asks customers whether they want to schedule a domestic or an international flight. Sixty-five percent of the reservations are for domestic flights. Callers then have the option of ...continues

Simulation: a. Conduct a 10-day simulation of this business using Row #1 below for demand and Row #2 below for rental length. b. You find out that your firm can obtain another car for $200 for 10 days. Should you take the extra car?

As the owner of a rent-a-car agency you have determined the following statistics: Potential Rentals Daily Probability Rental Duration Probability 0 .10 1 day .50 1 .15 2 days .30 2 .20 3 days .15 3 .30 4 days .05 4 .25 The gross profit is $40 per car per day rented. When there is demand for a c ...continues

Decision making with probabilities

Dollar Department Stores has received an offer from Harris Diamonds to purchase Dollar’s store on Grove Street for $120,000. Dollar has determined probability estimates of the store's future profitability, based on economic outcomes, as: P($80,000) = .2, P($100,000) = .3, P($120,000) = .1, and P($140,000) = .4. ...continues

Which test to use and why is it best?

I received three data sets (the data here are fictional to preserve confidentiality, but the point is the same): In 1998, a group of companies sold 1,000 units of Product A, 500 of B, 200 of C etc, for a total of 2000 units sold for ALL 8 of a set of 8 products. In 1999, the numbers were 900 for A, 400 for B, 300 for C etc, for ...continues

p-chart control chart using phstat

A hospital administrator was concerned with the time it took for patients' medical records to be processed after discharge. The hospital determined that all records should be processed within 5 days of discharge. Any record not processed within 5 days of discharge was considered to be non conforming. The number of patients disch ...continues