the correlation coefficient

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hypothesis_testing-hr_salary_for_directors.doc

CALCULATE T TEST

Calculate the “t” value for independent groups for the following data using the formula provided in the attached word document.   Using the raw measurement data presented, determine whether or not there exists a statistically significant difference between the salaries of female and male human resource managers using the appropriate t-test. Develop a  testable hypothesis, confidence level, and degrees of freedom. Report the required “t” critical values based on the degrees of freedom.  Show calculations.

Answer

The null hypothesis tested is

H0: There is no significant difference between the average salaries of female and male human resource managers. (µ1= µ2)

The alternative hypothesis is

H1: There is significant difference between the average salaries of female and male human resource managers. (µ1≠ µ2)

The test statistic used is

image1.wmf

12

12

2

~

NN

DM

MM

tt

S

+-

-

=

Where
image2.wmf

22

1122

1212

(1)(1)

11

2

DM

NsNs

S

NNNN

éùéù

-+-

=+

êúêú

+-

ëûëû

Here M1 = 62,200, M2 = 63,700

s1 = 9330.95, s2 = 6912.95

N1 = 10, N2 = 10 (See the excel sheet)

Then,

image3.wmf

(

)

(

)

22

(101)9330.95(101)6912.95

11

101021010

DM

S

éù

-+-

éù

=+

êú

êú

+-

ëû

êú

ëû

= 3672.267768

Therefore test statistic,

image4.wmf

62,20063,700

3672.267768

t

-

=

= -0.408466946

Degrees of freedom = N1 + N2 – 2 = 10 + 10 – 2 = 18

Let the significance level be 0.05.

Rejection criteria: Reject the null hypothesis, if the calculated value of t is greater than the critical value of t at 0.05 significance level. 

The critical values can be obtained from the student’s t tables with 18 d.f. at 0.05 significance level.

Upper critical value = 2.1

Lower critical value = -2.1

image5.wmf

0

.

4

0

.

3

0

.

2

0

.

1

0

.

0

X

D

e

n

s

i

t

y

-

2

.

1

0

0

.

0

2

5

2

.

1

0

0

.

0

2

5

0

D

i

s

t

r

i

b

u

t

i

o

n

P

l

o

t

T

,

d

f

=

1

8

Conclusion: Fails to reject the null hypothesis. The sample does not provide enough evidence to support the claim that there is significant difference between the salaries of female and male human resource managers.

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