In: Statistics and Probability
do males or female feel more tense or stress out at
work?A survey of employed adults conducted online revealed the
following. in the space below, draw a decision tree diagram and
answer the question a-d. your answer should be demonstrably derived
via decision tree.
a. Given that the employed adults felt tense or stress
out at work, what is the probability that the employed adults was a
male
b. Given that the employed adults is a male, what is
the probability that he felt tense or stress out at work
c. is the feeling tense or stress out at work and
gender independent
Yes.
No.
Sum
male.
244.
495.
739
Female.
282.
480.
762
Sum.
526.
975.
1501
a. Given that the employed adults felt tense or stress out at work, what is the probability that the employed adults was a male
required probability=P(male|tense)=P(male and
tense)/P(tense)=(244/1501)/(526/1501)=244/526=0.4639
b. Given that the employed adults is a male, what is
the probability that he felt tense or stress out at work
required probability=P(tense|male)=P(male and
tense)/P(male)=(244/1501)/(739/1501)=244/739=0.3302
c. is the feeling tense or stress out at work and
gender independent
here we use chi-square test with
null hypothesis H0: feeling tense or stress out at work and gender are independent
alternate hypothesis Ha: feeling tense or stress out at work and gender are not independent
chi-square=sum((O-E)2/E)=2.62 with (r-1)(c-1)=(2-1)(2-1)=1 df
critical chi-square(0.05,1)=3.84 is more than calculated chi-square , so we fail to reject(or accept) null hypothesis and conclude that feeling tense or stress out at work and gender independent
observed(O) | Expected(E) | E | (O-E) | (O-E)2/E | |
244 | 526*739/1501 | 258.97 | -14.97 | 0.87 | |
495 | 975*739/1501 | 480.03 | 14.97 | 0.47 | |
282 | 526*762/1501 | 267.03 | 14.97 | 0.84 | |
480 | 975*762/1501 | 494.97 | -14.97 | 0.45 | |
sum= | 1501 | 0 | 1501 | 0 | 2.62 |