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Histogram

A histogram is used in statistics to visually present a frequency distribution for different category boundaries, through the construction and juxtaposition of rectangular bars. Histograms are very frequently used in statistics to visualize data because they provide an effective and simple method for presenting the frequency of particular values for a data set or independent variable. After constructing a frequency distribution, histograms are commonly the subsequent step in presenting the data.

Histograms are similar in appearance to bar graphs, but unlike bar graphs, there are no spaces between the bars of histograms. Additionally, histograms can be used to represent numerical data that is provided by intervals, which is common when graphing the data from a frequency distribution. Thus, each of the bars can be marked by boundaries.

Additionally, histograms are also used frequently in statistics to test for normality and inspect whether any irregularities are associated with the data. A test for normality indicates whether or not the data follows a normal distribution. A test for irregularities may analyze whether or not more than one pronounced peak exists within the data set for example.

Figure 1. This is a histogram in which the differences calculated for the height between the galled and ungalled plants is plotted. These differences were calculated by calculating the height difference for the entire sample size (n=164) between the galled and ungalled plants. This histogram is used to test for normality.

Figure 1 above, presents an example of a histogram being constructed for an ecological situation. As is mentioned in the figure caption, this histogram was used to test for normality. From a quick visual inspection, the pattern of the bars, resembling a bell shaped curve, indicates that the data for the variable being measured follows a normal distribution.

Descriptive Statistics and Histogram

Question 2 The U. S. Department of the Interior releases figures on mineral production. The following are the 15 leading states in nonfuel mineral production in the United States in 2008. State Value ($ billions) Arizona 7.84 Nevada 6.48 Florida 4.2 Utah 4.17 California 4 Texas 3.8 Minnesota

Interpretation of independent t tests (SPSS output)

I need help with interpretation. I have included the actual data that was used in SPSS statistics as well as the Outputs. I have attached everything that I have below. Can you please help me once again with the interpretation of information?

Statistical Analysis: Quality of Service

One of the major measures of the quality of service provided by any organization is the speed with which it responds to customer complaints. A large family-held department store selling furniture and flooring, including carpet, had undergone a major expansion in the past several years. In particular, the flooring department had

National Survey of Student Engagement surveys: histogram, distribution

The National Survey of Student Engagement (NSSE) surveys freshmen and seniors about their level of engagement in campus and classroom activities that enhance learning. Hundreds of thousands of students from over 1,200 schools have completed surveys since 1999, the first year that the NSSE was administered. Among the many quest

Calculation of Percentages

Repack Solutions, Inc. has a distribution center in Cincinnati where it receives and breaks down bulk orders from suppliers' factories, and ships out products to retail customers. Prepare a chart showing the different quality cost categories and percentages for the company's quality costs that were incurred over the past year. W

Histogram and relative frequency

Please help with the following problems. See attached file for proper table format. Accounting Horizons published a 1998 study in which corporate executives reported the number of times each year they held audit committee meetings with the chief internal auditor of the corporation. The raw data are shown below: 0 0 0 0 0

Ads for ADT Security Systems claim

1. The Public Health Service studied the effects of smoking on health, in a large sample of representative households. For men and for women in each age group, those who had never smoked were on average somewhat healthier than the current smokers, but the current smokers were on average much healthier than those who had recently

Statistical Analysis

1. A production manager is interested in determining the variability in the proportion of defective items in a shipment in one of the computer components that her company manufactures. The spreadsheet provided contains the proportion of defective components for each of the 500 randomly selected shipments collected during the one

Forecast Future Inventory Costs

Summer Historical Inventory Data Typical Seasonal Demand for Summer Highs Actual Demands (in units) Month Year 1 Year 2 Year 3 Year 4 Forecast 1 18,000 45,100 59,800 35,500 2 19,800 46,530 30,740 51,250 3 15,700 22,100 47,800 34,400 4 53,600 41,350 73,890 68,000 5 83,200 46,000 60,200 68,100 6

Statistics: Compute range, mean, various, deviation, distribution

Excel: All problem sets and answers must be in Excel. #1: Prepare answers to the following: The annual incomes of five vice-presidents of TRW Inc. are: $125,000, $128,000, $122,000, $133,000, and $142,000. Consider that is the entire population and compute: a. Range, b. The arithmetic mean income and the median income, c

Histograms for Grouped Data: Length of stay in days in a hospital

The following are the lengths of stay (in days) for a random sample of patients discharged from a particular hospital: 13, 9, 5, 11, 6, 3, 12, 10, 11, 7, 3, 9, 9, 4, 4, 2, 2 Draw the histogram for these data using an initial class boundary of 1.5 , an ending class boundary of 13.5, and 6 classes of equal width. Note that you

Histograms: What shape of sample; value of estimate; standard deviation

A population has a mean of 79 and a standard deviation of 27. Sample means are computed for several thousand random samples of size ? = 81, and a relative frequency histogram is constructed for the sample means. 1. What kind of shape would you expect the histogram of the sample size to have? 2. What value would you es

Drawing Conclusions for Ambulance Departments

Between mar, 1, 1994 and aug 31, 1994, all calls that involved both ambulance and fire department personnel were monitored. The times for each service to arrive at the scene were recorded using the following format: Column 1: call number for Cambridge calls Column 2: time in minutes for fire truck to arrive Column 3: time i

Standard Deviations and Variables

(a) Find the following for variables A and B: mean, median, mode and standard deviation. (b) Create a histogram for variables A and B and create a scattergram between variables A and B (c) Compute the coefficient correlation between variables A and B Variable A: Variable B:

Sampling and histograms

Please help with the following problems involving sampling and histograms. a. A graduate student is conducting research in psychology and she needs to obtain the IQ scores of 50 people. She places an ad in the local newspaper and asks for volunteers, each of whom will BE PAID $50 to take the IQ test. Is her sample a good sam

Normally Distributed Histograms

1. What shape would your distribution histogram be if the variable is approximately normally distributed? 2. True or False. As the amount of confidence increases, the required sample size should decrease. Explain your answer.

Cigarette Advertisement Case Study

The solution addresses the tobacco industry case. Tobacco industry representatives have steadfastly maintained that code provisions are still being observed. A 1988 Tobacco Institute publication, "Three Decades of Initiatives by a Responsible Cigarette Industry," refers to the industry code as prohibiting advertising and prom

Webster Mail Order Company - Histogram

The Webster Mail Order company sells expensive stereos by mail. The following table lists the frequency distribution of the number of orders received per day by this company during the past 100 days. # of orders received per day: 2 3 4 5 6 Number of days: 12 21 34 19 14 a. Construct a probability distribution table for

Histogram: Effectiveness of a Treatment

To evaluate the effectiveness of a treatment, researchers will often measure individuals before and after treatment, and record the amount of difference between the two scores. If the differences average around zero, it is an indication that the treatment has no effect. However, if the differences are consistently positive (or c

Stem and Leaf, Frequency Histogram

2.19 A company executive has read with interest the finding that the average U.S. office worker receives 36 e-mails per day. Assume that an executive, wishing to replicate this study within her own corporation, directs information technology personnel to find out the number of e-mails each of a sample of 100 office workers recei

Coins Sample Histogram

I am trying to figure out how to enter data to create a histogram based on the following info. I want to create the histogram based on the cumulative frequency distribution. Any help is appreciated. Thanks. Pennies by Year: Year # of Coins 1967 3 1968 2 1969 2 1970 1 1971 1 1972 2 1974 1 1975 1 1976 1 1977 3 19

Displaying Data in a Histogram

I need help in how to display the following data in a histogram. Can you provide step by step advice on how I can go about solving this problem? 1. Display the frequency distribution of the salaries graphically in a histogram (choose intervals to use along the horizontal axis) and tell what is the mean, median and ske

Frequency Histogram and Proportion

In a relative frequency histogram for a large set of GPAs, the mean and the standard deviation are 2.10 and 0.21 respectively. What proportion of GPAs falls within 1.68 and 2.52? What about the proportion of measurements that are at most 1.89? Discuss how you arrived at these results.

Standard Deviation of a Sample

Excel Lab 2 For this assignment, choose a single variable data set that interests you from (except the "Motion of Stars" data set which I'll use for my example): http://college.hmco.com/mathematics/brase/understandable_statistics/8e/students/datasets /sv/index.html or on the CD that came with your text. Follow the link,

Histograms and Probabilities

Manufacturing plants A and B produce sports shoes. The following are the data for plant A: 39, 32, 34, 40, 45, 35, 54, 36, 40, 41, 55, 43, 44, 46, 47, 49, 51, 54, 59, 46 The following are the data for Plant B: 27, 37, 29, 44, 31, 33, 34, 46, 58, 59, 32, 32, 55, 57, 63, 33, 56, 58, 62, 51 a) Make a histogram, one above

Histogram and Level of Significance

A civil service exam is given to 200 job applicants. In recent years, grades have followed a normal distribution with mean 66.5 and variance 100. The grades of the job applicants are distributed as follows: Grades Observed Frequency Under 49.5 22 49.5 - 59.5 38 59.5 - 69.5 56 69.5 - 79.

Relative frequency histogram questions

A nurse measured the blood pressure of each person who visited her clinic. Following is a relative-frequency histogram for the systolic blood pressure readings for those people aged between 25 and 40. Use the histogram to answer the questions below. The blood pressure readings were given to the nearest whole number. 1. Approx