April 24, 2023

normal-

Review course text and Moodle notes on the Normal Distribution

Review this article on the Normal Distribution applied to business salary problems https://www.wallstreetmojo.com/normal-distribution/

1) Select one continuous variable from the Student Generated Class Database. and name the variable,

StudentClassID:34

DegreeProgram:MBA

NumberOfDegrees:1

StatisticsPreception:Difficult

Sex:Female

NumberOfSiblings:4

CityPopulation:14493

NumberPriorStatCourses1

RateStatExperienceNovice

Do you have Children?No

Rank your comfort with using JASPDifficult

Rank of comfort with using ExcelVery Difficult

Are your left or right handed?Right

Rate your Math ComfortabilityProficient

Tags:

2) generate ONE piece of evidence (numerical summaries, tables, or charts) that supports or refutes that the variable you selected may potentially be normally distributed. 3) attach your generated evidence (numerical summaries, tables, and/or charts) to your post, and 4) discuss how you are justifying your claim of for or against normality be referencing your evidence. APA formatting is ALWAYS expected.

In your post, number your )responses (as above) so that it is clear what you are responding to

Continuous Distributions

Continous Probability Distributions: data values are measured and not counted
	a probability DENSITY functions represented by mathematical functions
	probabilities are calculated within ranges and not at specific values: P(a) is theoretically 0 but Excel does estimate the height of the probability density curve at 'a'
			Shape	Range	Other
		Normal	Bell Shaped	negative infinity to infinity	mean = median
		Uniform	Rectangular & symmetric	a to b	mean = median
		Exponential	Skewed right	0 to infinity	mean>median
	Normal Distribution Benefits
		Many variables in business can be represented using a normal distribution
		Used to approximate discrete probability distributions
		can be completely defined (with it's mathematical function) with the mean and standard deviation
			N(mean, standard deviation)

normal

Calculating Normal Distribution Probabilities with Excel
	Excel transforms Xi data values to Z scores before calculating probabilties
	the standard normal distribution is used to determine the probablities
		Use NORMDIST in Excel
	Example
		You need
		Mean=		10
		Standard Deviation =		2
			STANDARDIZE	NORMDIST	1-NORMDIST
		Xi	Z-score	P(X<Xi)	P(X>Xi)		To find probability of ranges
		7	-1.5	0.0668072013	0.9331927987		P(Xa<X<Xb)=ABS(P(X<Xb)-P(X<Xa))
		5	-2.5	0.0062096653	0.9937903347
		9	-0.5	0.3085375387	0.6914624613	Probability of age between 8 and 12 ?
							0.6826894921

=NORMDIST(Xi, mean, s, False)

=STANDARDIZE(Xi, mean, s)

problem samples

Calculating data values of a normal distribution when the corresponding Z score or probabilities are given
				WHat is the X value associated with Z-Score = 1.5?
	You Need				73.75
		Mean=	70
		STandard Deviation =	2.5
				What is the X value for the distribution where p = .35 for values less than X?
						69.036698834
				What is the Z-score value for the distribution where p = .35 for values less than Z?
						-0.3853204664

=NORMINV(p, mean, s)

=NORMSINV(p)

=mean + Z(s)

normality

Is the Data distribution approximately normal?

check the histogram

examine the descriptive statistics

use a normality plot

Plot A

Plot B

Mean and median should be near equal

bell-shaped histogram

Dots are close to line

Suggests the distribution is approximately normal in shape

Empirical Rule

Need a bell-shaped distribution to use the Empirical Rule
Age
80	Age Desciptive Statistics					Approximately:
91							68% of data values are within 1 standard deviation of the mean
77	Mean	79
85	Standard Deviation	9.5694384163					95% of data values are within 2 standard deviation of the mean
71
89							99.7% of data values are within 3 standard deviations of the mean
82
79
74
68	Question1: Approximately what percent of the age data is within 1 standard deviation unit of the mean?
103			According to the Empirical Rule, approximately 68% of the age
92			data is within 1 standard deviation above and below the mean
85
81	Question2: Within what interval are approximately 68% of the age data values? (Hint: need standard deviation of the distirbution)
82			According to the Empirical Rule
64				lower bound	69.5352344046
81				upper bound	88.6741112372
84
100
86
83
67
84
78
63
70
85
99
93
79
88
69
86
103
85
73
61
71
89
98
71
81
83
81
69
65
77
82
80
78
60
71
71
73
86
84
79
77
85
72
83
89
85
91
73
76
87
73
86
85
78
94
79
76
79
76
64
78
65
71
72
68
81
84
77
68
70
82
66
81
82
79
55
99
68
74
80
76
89
69
79

Generating data

Generate Normal distribution of data in Excel
		Mean	10
		Standard deviation	2
	11.5819814265			Use Copy …Paste … Paste Special … Values
	8.3738684914				To keep data from continuing to update due to the RAND() feature
	9.0864744902
	9.2572957454
	9.3909571118
	13.7527527534
	10.8007385469
	4.0893192297
	8.9700785395
	9.2928090436
	8.8604097223
	6.4852175137

image1.png

image2.png

image3.png

image4.png

image5.png

image6.png

image7.png

Chapter 5 and 6 notes Discrete and Continuous Probability Distributions

Discrete Probability Distributions

Discrete Probability Distribution Learning Objectives • Distinguish bet

Collepals.com Plagiarism Free Papers

Are you looking for custom essay writing service or even dissertation writing services? Just request for our write my paper service, and we'll match you with the best essay writer in your subject! With an exceptional team of professional academic experts in a wide range of subjects, we can guarantee you an unrivaled quality of custom-written papers.

Get ZERO PLAGIARISM, HUMAN WRITTEN ESSAYS

Why Hire Collepals.com writers to do your paper?

Quality- We are experienced and have access to ample research materials.

We write plagiarism Free Content

Confidential- We never share or sell your personal information to third parties.

Support-Chat with us today! We are always waiting to answer all your questions.