# 8230 Unit VI Assessment Final

**Topics:**Normal distribution, Statistics, Arithmetic mean

**Pages:**9 (1440 words)

**Published:**July 4, 2015

Unit VI Assessment

Doctorate

Of

Business Administration Degree

Dhana K. Jones

Columbia Southern University

DBA 8230-11C

Dr. Castle

January 15, 2015

Unit IV Assessment

Question 1

Descriptive statistics refers to examining data to determine average, mode, median, kurtosis, skewness, and correlation. Statistical average is referred to as the mean. Researchers determine the mean by dividing the sum of observed values by the number of observations (n). Field (1998) states, statistical average (mean) boils down to the equation outcome = (model) + error (pg. 39). The mean is a good estimate for predictive statistical research.

Standard deviation is a measure of the data spread and it is signified by the Greek letter sigma (σ). The standard deviation requires calculation of the average, compare each respondent’s value to the average, and square that difference (Burns & Bush, 2012, pg. 252). Therefore, the formula for standard deviation is the square root of the variance. The variance is the average of the squared differences of the mean. The standard deviation explains the density of data scattered around the mean. Curve distribution is a bell shaped curve when data is tightly bunched together. Highly arched bell shaped curves have a small standard deviation. Flat bell shaped curves have a large standard deviation.

A normal distribution of data indicates a section of data that are close to the average. The average is located at the curves center or midway point. The standard deviation is located on either side of the midway point. Normally distributed data is shaped as a bell curve. The proportion of data under the curve and within + or – 2.96 standard deviation describe the range that 99% of data is found (Burns & Bush, 2012, pg. 253).

Statistics

Purchase Price

Closing Date

Days on Market Before Sold

Home Size in Sq Ft

N

Valid

94

94

93

94

Missing

0

0

1

0

Mean

$256,159.57

03/17/2000

49.53

2540.96

Median

$281,000.00

03/20/2000

53.03

2687.50

Mode

$135,000

01/01/2000

1a

3112

Std. Deviation

$79,695.294

111 03:45:59.014

33.397

954.719

Skewness

-.552

-.161

.257

-.338

Std. Error of Skewness

.249

.249

.250

.249

Kurtosis

-.898

-1.233

-.975

-.688

Std. Error of Kurtosis

.493

.493

.495

.493

Range

$298,000

371 00:00:00

132

3978

a. Multiple modes exist. The smallest value is shown

References

Burns, A. C., & Bush, R. F. (2012). Basic Marketing Research. (S. Yagan, Ed.) Upper Saddle River, NY, US: Pearson Education Inc.,. Field, A. (1998). Discover Statistics Using SPSS (Third ed.). (S. Publication, Ed.) London, UK: Sage Publication.

Question 2

The method for determining a confidence interval to estimate a population average requires a descriptive statistical data analysis that provides the sample mean, standard deviation, standard error, and sample size. Interpretation of confidence intervals is the same process regardless if the percentage or average is examined. Regardless of the amount of times a descriptive data analysis is completed, the reading remains the same (Burns & Bush, 2012, pg. 273). Researchers commonly use the 95% confidence interval formula to estimate a population mean. Therefore, researchers determine the sample mean, standard deviation, standard error, and the limit. Researchers calculate the limit by multiplying the standard error. The 95% confidence interval is the space between the lower and upper boundary. Subtracting or adding the limit to the average determines the lower and upper boundary (Burns & Bush, 2012, pg. 273). Researchers use confidence intervals to state a hypothesis within a 95% confidence rate. Market researchers examine confidence intervals to determine the mean increase in product effectiveness. Therefore, researchers use confidence intervals to construct a range of values within which they think the population value falls (Field, 1998, pg. 43). Marketing researchers must ensure they...

References: Burns, A. C., & Bush, R. F. (2012). Basic Marketing Research. (S. Yagan, Ed.) Upper Saddle River, NY, US: Pearson Education Inc.,.

Leedy, P. D., & Ormrod, J. E. (2010). Practical Research. (J. Johnson, Ed.) Upper Saddle River, NY: Pearson.

Leedy, P. D., & Ormrod, J. E. (2010). Practical Research. (J. Johnson, Ed.) Upper Saddle River, NY: Pearson.

Burns, A. C., & Bush, R. F. (2012). Basic Marketing Research. (S. Yagan, Ed.) Upper Saddle River, NY, US: Pearson Education Inc.,.

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