Explore BrainMass

Dispersion and Spread of Data

Payne (2001) Gave Participants a Computerized Task - Mean and Standard Deviation

Payne (2001) gave participants a computerized task in which they first see a face and then a picture of either a gun or a tool. The task was to press one button if it was a tool and a different one if it was a gun. Unknown to the participants while they were doing the study, the faces served as a "prime" (something that starts y

Distribution of Weights for Samples

I simply need help with setting up the formula or an example of how to complete the problem on my own. I have been reading the topics but nothing explained what formula to use to get the answer so can someone please show me the steps so I can compute it myself. 1.) The distribution of weights for a sample of 1,400 cargo co

Standard Deviation for Psychology Exam

For a particular sample of 50 scores on a psychology exam, the following results were obtained. First quartile = 67 Third quartile = 91 Standard deviation = 9 Range = 48 Mean = 75 Median = 80 Mode = 81 Midrange = 74 a)What score was earned by more students than any other score? Why? b)How many students scored b

Summation Notation, Percentile and Proportion

Please show your work. I am having trouble working out the problems. I would like as detailed an explaination for the answers as you can give. 1. A teacher gives a 20-point quiz to 10 students. The scores are listed below. What percentile corresponds to the score of 12? 20 8 10 7 15 16 12 19 14 9 A. 13 B. 40 C.

Basic Statistics and Bar Graphs

1. Find the first and third quartiles, Q1 and Q3, of the following set of numbers. 0.16, 0.08, 0.27, 0.20, 0.22, 0.32, 0.25, 0.18, 0.28, 0.27 a. 0.16; 0.28 b. 0.18; 0.27 c. 0.16; 0.27 d. 0.18; 0.28 2. Continent or Region Land Area (1,000 mi2) % of Earth Population 1900 Population 1950 Population 2000 North Am

Development of a Test to Measure Depression

Dr. Zak Case Study INSTRUCTIONS Read the following case study. Then, use the information in the case study to answer the accompanying follow-up questions. Although questions 1-2 have short answers, you should prepare a 150 to 200-word response to each of the remaining questions. CASE STUDY Dr. Zak developed a test to measure

15 Problems : Five-Number Summary, GCF, Factorization, Perimeter and Area

4. Jamal is fencing a rectangular field that measures 40 ft by 15 ft. How much fencing should he buy? 7. Find the prime factorization of the number 360. 8. Find the greatest common factor of 16, 12, and 100. 13. Find the least common multiple of 15 and 21. 18. Jacque earns $9.60 per hour (h). For overtime (each h

Normal Distribution: First Mortgage

The average conventional first mortgage for new single-family homes was $294,000. Assuming a normal distribution and a standard deviation of o = $30,000, what proportion of the mortgages were: a. more than $294,000? b. between $234,000 and $354,000? c. between $264,000 and $342,000? d. more than $204,000?

Time Measurement and Histogram Construction

1. A psychologist is studying the length of time it takes mice to go through a maze and reach a reward at the end. Time is measured to the nearest tenth of a second with the results given in the table below. Time Frequency 2.0 up to 3.0 3 3.0 up to 4.0 7 4.0 up to 5.0 15 5.0 up to 6.0 29 6.0 up to 7.0 81 7.0 up to 8.0

Statisitics: Mean, Median, Mode and Pie Charts

Please see the attached file for the fully formatted problems. 1. Find the mean of the following set of numbers. 13, 15, 18, 18, 18, 19, 22, 26, 28, 33 2. Find the median of the following set of numbers. 24, 26, 31, 33, 35, 36 3. Find the mode of the following set of numbers. 22, 55, 43, 26, 33, 36, 43, 2

Age Distribution of Prehistoric Native Americans

This is a 3 step problem requested as an example however we have not gone over how to do this yet, I need help with understanding these steps. I have a chart with the greek letters and numbers but am not sure how to put this in order. It is requested to answer and show work so whatever help you may offer will help me better unde

Predicting Mean and Standard Deviation

If the sampled population has a mean of 48 and a standard deviation of 16, then the mean and the standard deviation for the sampling distribution of x -bar for n = 16 is?

Basic statistics: mean, variance and standard deviation

1. Plywood, Inc. reported these returns on stockholder equity for the past 5 years: 4.3, 4.9, 7.2, 6.7, and 11.6. Consider these as population values. a. Compute the range, the arithmetic mean, the variance, and the standard deviation. 2. The annual incomes of the five vice presidents of TMV Industries are: $125,000; $128,0

Expected Value and Standard Error

For a sample selected from a population with a mean of u=50 and a standard deviation of o=10: what is the expected value of M and the Standard error of M for a sample of n=4 scores?

Prime numbers, fractions, etc

(See attachment for details) 11 A baseball player scored a total of 27 runs in the first 20 games of the season. If he continues at the same pace, how many runs should he score in the 80-game season? Show Work Below 12 Estimate the result in the following division problem. (Remember to round divisors to the neares


Given the following data set, find the value that corresponds to the 75th percentile. 10, 44, 15, 23, 14, 18, 72, 56

Graphing and Basic Statistics

Please see the attached for the math questions I need help with. 1. The following table gives the population of certain states according to the 2000 census. State Population Illinois 12,419,293 New Jersey 8,414,350 New York 18,976,457 Tennessee 5,689,283 Texas 20,851,820 Construct a bar graph from this informat

Estimating the Population Mean

SEE ECCO INFO ATTACHED The quality manager at Ecco Company, a maker of back-up alarms for use on industrial vehciles such as forklifts, is interested in estimating the mean dollar volume for warranty claims for products made in Boise on the day shift. He has taken a pilot sample. See info attached. a. Assuming that the

Random Sampling and Error

6.1 Consider the following data to be a population of N=20 values ______________________________________________________________ 5 3 2 6 6 7 3 3 6 7 7 9 7 5 3 12 6 10 7 2 ___________________________

Confidence Interval and Random Sample

1. A confidence interval for a population mean has a margin of error of 10.7. What is the length of the confidence interval? 2. A random sample of size 17 is taken from a population. A normal probability plot of the sample data is found to be very close to linear. The population standard deviation is unknown. The appropriate m

Probability and Standard Deviation Questions

1. The time that the customers at the "self serve" check out stations at the Mejers store spend checking out follows a uniform distribution between 0 and 3 minutes. a. Determine the height and draw this uniform distribution. b. How long does the typical customer wait to check out? c. Determine the standard deviation of the

Probability & Standard Deviation

14. A file cabinet manufacturer estimates that 5% of its file cabinets will have drawers that close improperly. Assume a production run of 120 cabinets is completed. a. What is the mean and standard deviation of this distribution? b. What is the probability that 7 or more are defective? c. What is the probability that exactly

Standard Deviation

The true length of boards cut at a mill with a listed length of 10 feet is normally distributed with a mean of 123 inches and a standard deviation of 1 inch. What proportion of the boards will be over 125 inches in length?

What do you think the market shares will be next month?

Over any given month, Dress-Rite loses 10% of its customers to Fashion, Inc., and 20% of its market to Luxury Living. But Fashion, Inc., loses 5% of its market to Dress-Rite and 10% of its market to Luxury Living each month; and Luxury Living loses 5% of its market to Fashion, Inc., and 5% of its market to Dress-Rite. At the p

Probability calculations based on normal probability

1. Suppose that the random variable x is normally distributed with mean = 1,000 and standard deviation = 100. Sketch and find each of the following probabilities: a. P(1,000<_x<_1,200) e. P(x<_700) b. P(x>1,257) f. P(812<_x<_913) c. P(x<1,035) g. P(x>891) d. P(85

Mean and Standard Deviations

Advertising expenses are significant component of the cost of goods sold. Listed below is a frequency distribution showing the advertising expenditures for 60 manufacturing companies located in the Southwest. Estimate the mean and the standard deviation of advertising expense. See attached file for chart.

Quartiles, deciles, and various percentiles.

The Thomas Supply Company, Inc. is a distributor of small electrical motors. As with any business, the length of time customers take to pay their invoices is important. Listed below, arranged from smallest to largest, is the time, in days, for a sample of The Thomas Supply Company, Inc. invoices. a. Determine the first and t