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# Dispersion and Spread of Data

### Box and Whisker Plots

A box and whisker plot is used to display data. Explain what box and whisker plots shows us. Provide example. Thanks.

### Portfolio: expectation, standard deviation and covariance

An investor wants to invest 1000 euro. He can choose between the shares of the electronic company Solips and the food supply chain Bhold. The value of the first share is 1 euro at the moment the investment is made, the price of the second share is 2 euro. How should the investor divide the 1000 euro between the two types of shar

### Relationship of Mean and Standard Deviation

Please see the attached MS Word Document. It shows a table with three variables and the min, max, mean and SD for the each variable. I'm trying to determine what the rlationship is between the mean and SD for each variable. Introduction to Social Research Methods As part of an assignment I am working on I have the followin

### Estimating Mean Germination Time of Strawberry Seeds

Suppose that we want to estimate the mean germination time of strawberry seeds. The germination times for the sample of strawberries we choose has a mean of days and a standard deviation of days. For each of the following sampling scenarios, determine which test statistic is appropriate to use when making inference statements

### Statistics

You are given the following data for the number of times a population of six families dined out during the previous month: 4 6 9 4 5 7 a. Compute the mean, median and mode for this data. b. Compute the range for this data. c. Compute the variance and standard deviation. d. Assume that these data represent a sample rat

### Booking/Overbooking at SleepyTime Hotel: Early and Late Booking Demand and Standard Deviation

The manager of the 420-room SleepyTime Hotel is trying to decide how many rooms to reserve for vacationers who book less than two weeks in advance. Demand for the "early booking" rooms is unlimited at the price of \$240/day. Demand for the "late booking" rooms averages around 120 rooms/day, and varies by about 15 rooms/day. Th

### Random Variables- Properties of Variance/Standard Deviation

A mason is contracted to build a patio retaining wall. Plans call for the base of the wall to be a row of 50 10-inch bricks, each separated by ½ inch thick mortar. Suppose that the bricks used are randomly chosen from a population of bricks whose mean length is 10 inches and whose standard deviation is 1/32 inch. Also suppose

### The mean price of 7 Hewlett Packard computers is \$815 with a standard deviation of \$19.

The mean price of 7 Hewlett Packard computers is \$815 with a standard deviation of \$19. The mean price of 9 IBM computers is \$845 with a standard deviation of \$9. If the alpha value is 0.05, can a computer shopper conclude that the IBM computers cost more? a. yes, there is enough evidence to conclude IBM computers cost more

### Intro to Statistics Question

What kind of test is used if the population standard deviation is not known and is less than 30?

### Sample and Population Standard Deviation, Mean and Variance

1. What are standard deviation, mean, and variance for sample and populations and what Greek letters represent them? Give examples please.

### Word Problem

At the time she was hired as a server at a restaurant, Beth was told she could average more than \$20.00 a day in tips. Over the first 35 days she was employed, the mean daily amount of her tips was \$24.85, with a standard deviation of \$3.24. At the .01 significance level, can Beth conclude that she is earning an average of more

### Calculating the mean and variance for different portfolios.

Calculating the mean and variance for different portfolios. David wants to invest his \$4 million inheritance. He walks into Stock-o-rama and examines the information about four particular stocks. David will sell his stocks after exactly one year. Each of the stocks will pay out a particular amount in one year, times the a

### Testing a claim given a confidence level, mean and standard deviation.

Sample data was collected in a study of calcium supplements and their effects on blood pressure. A placebo group and a calcium group began the study with blood pressure measurement. At a 0.05 significance level, test the claim that the 2 sample groups come from populations with the same mean. Placebo mean: 114.6538, standard d

### Bumper Installation Standard Deviation

The time taken to install bumpers on cars passing through a particular assembly line is normally distributed with mean time u=2.00 minutes and standard deviation =36 minutes. A sample on n=100 is obtained and a mean bumper installation time X-bar will be calculated. 1. Find the value of standard deviation X bar. Determine th

### Determining the Probability using Mean and Standard Deviation

The weights of adult Americans are normal with a mean of 164 lbs. and a standard deviation of 24 lbs. Two random samples are taken with 10 adult Americans in each sample. (a) What is the probability that both samples have a mean greater than 180 lbs.? (b) What is the probability that, when the two samples are put together,

### Statistics Problem

1. Bill has completed a ten question multiple choice test on which he answered seven questions correctly. Each question had one correct answer to be chosen from four alternatives. Bill says that he answered the test by randomly selecting the answers without reading the questions or answers. a. What is the expected number of

### Simple Statistical Excel Functions and Formulas

Let's say I have two columns of numbers (5 in each column). 1/ Pls. advise of the following functions' FORMULA in excell: percentile range rank weighted average confidence correlation forecast 2/ and elaborate as to WHAT that function is telling me (how is it useful)?