GB6023 Tutorial 2: Jadual Kontigensi dan Normal Distribution
Jadual Kontigensi. 1.
GENERAL HAPPINESS * Respondent's sex Crosstabulation
Respondent's sex
Total Male Female
GENERAL HAPPINESS VERY HAPPY Count 189 246 435
% within Respondent's sex 30.9% 31.7% 31.3%
PRETTY HAPPY Count 350 447 797
% within Respondent's sex 57.2% 57.5% 57.4%
NOT TOO HAPPY Count 73 84 157
% within Respondent's sex 11.9% 10.8% 11.3%
Total Count 612 777 1389
% within Respondent's sex 100.0% 100.0% 100.0%
Jawab soalan berikut: a. Apakah pembolehubah bersandar dan
pembolehubah bebas? b. Berikan ulasan terhadap data dari jadual
kontigensi tersebut.
2.
GENERAL HAPPINESS * MARITAL STATUS Crosstabulation
MARITAL STATUS
Total MARRIED WIDOWED DIVORCED SEPARATED
NEVER
MARRIED
GENERAL
HAPPINESS
VERY HAPPY Count 266 36 47 9 77 435
% within MARITAL
STATUS
42.4% 26.3% 20.8% 16.4% 22.4% 31.3%
PRETTY
HAPPY
Count 332 71 148 32 214 797
% within MARITAL
STATUS
53.0% 51.8% 65.5% 58.2% 62.2% 57.4%
NOT TOO
HAPPY
Count 29 30 31 14 53 157
% within MARITAL
STATUS
4.6% 21.9% 13.7% 25.5% 15.4% 11.3%
Total Count 627 137 226 55 344 1389
% within MARITAL
STATUS
100.0% 100.0% 100.0% 100.0% 100.0% 100.0%
a) Apakah pembolehubah bersandar dan pembolehubah bebas? b)
Berikan ulasan terhadap data dari jadual kontigensi tersebut.
Normal Distribution 1. The random variable Z has = ______ and =
_____.
2. P(0 < z < 1.53) =
3. P( z > -2.18) =
4. Find the value of zo, such that P( -zo < z < zo) =
.92.
5. Find the value of zo, such that P(z < zo) = .3015.
6. The random variable X is normally distributed with mean 80
and standard deviation 12.
a) What is the probability that a value of X chosen at random
will be between 65 and 95? b) What is the probability that a value
of X chosen at random will be less than 74?
7. The random variable X is normally distributed with mean 65
and standard deviation 15. Find xo, such that P(x > xo) =
.6738.
8. The scores on a placement test have a mound-shaped
distribution with mean 400 and standard deviation 45.
a) What percentage of people taking this exam will have scores
of 310 or greater?
b) What percentage of the people taking this test will have
scores between 445 and 490?
9. A test has been devised to measure a student's level of
motivation during high school. The motivation scores on this test
are approximately normally distributed with a mean of 25 and a
standard deviation of 6. The higher the score the greater the
motivation to do well in school.
a) What percentage of students taking this test will have scores
below 10?
b) John is told that 35% of the students taking the test have
higher motivation scores than he does? What was John's score?
