A sample data set has a mean of 57 and a standard deviation of 11. Determine whether each of the following sample measurements are outliers.

a.65

b.21

c.72

d.98

Short Answer

Expert verified

(a) Not an outlier

(b) Outlier

(c) Not an outlier

(d) Outlier

Step by step solution

01

Determining whether 65 is an outlier

We will use the z- score methodz=Value-MeanStandarddeviation=65-5711=811=0.727

As the z score < 3, 65 is not an outlier.

02

Finding whether 21 is an outlier

z=Value-MeanStandarddeviation=21-5711=-3611=-3.27

21 is an outlier

03

Calculating whether 72 is an outlier

z=Value-MeanStandarddeviation=72-5711=1511=1.36

72 is not an outlier.

04

Calculating whether 98 is an outlier

z=Value-MeanStandarddeviation=98-5711=4111=3.727

98 is an outlier.

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Most popular questions from this chapter

Surface roughness of oil field pipe.Oil field pipes are internally coated to prevent corrosion. Researchers at the University of Louisiana, Lafayette, investigated the influence that coating may have on the surface roughness of oil field pipes (Anti-corrosion Methods and Materials, Vol. 50, 2003). A scanning probe instrument was used to measure the surface roughness of each in a sample of 20 sections of coated interior pipe. The data (in micrometers) are provided in the table.

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a) The average financial aid awarded values were determined by recording the financial aid awarded to each freshman who attended the university in 2015. Does this statistic represent a population or sample mean? Interpret this value for Harvard University.

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Rank

University

Public/

Private

Academic Reputation Score

(100 pt. scale)

Average Financial Aid Awarded

Average Net Cost Attend

Median Salary During Early Career

% High Meaning

%Stem Degrees

1

Harvard University

Private

99

\(41,555

\)14,455

\(61,400

65%

28%

5

Yale University

Private

97

\)39,771

\(18,479

\)60,300

68%

21%

20

University of

California Berkeley

Public

79

\(16,141

\)16,178

\(59,500

50%

31%

23

University of Virginia

Public

76

\)16,834

\(12,672

\)54,700

52%

24%

27

Carnegie Mellon

University

Private

76

\(24,263

\)33,257

\(64,700

46%

51%

47

Pepperdine University

Private

60

\)29,926

\(25,345

\)48,300

51%

4%

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