Business Stat

GROUP 2

CHAN KA LOK

50966632

MC

1. B
2. A
3. D
4. C
5. D
6. B
7. D
8. C
9. D
10. A
11. B
12. A
13. A
14. B
15. D
16. D
17. B

LQ

1)

There are 25 people conducted this survey and 11 people rated 50 or below.

11/25 x 100%

=44.0000%

The percentage of the respondents rated overall television quality with a rating of 50 or below is 44.0000%.

2)

Let A be the number of the residents own 2 cars.

Let A’ be the number of the residents not own 2 cars.

Let B be the number of the residents’ annual household income is over $25,000.

Let B’ be the number of the residents’ annual household income is not over $25,000.

P (A l B) = P (A and B)/ P (B)

0.8 = P (A and B)/ 0.6

P (A and B) = 0.4800

The probability that the residents of a household do not own 2 cars and have an income over $25,000 a year is 0.1200.

3a)

We have to prove P (A and B) = P (A) P (B)

L.S = P (A and B)

   = 0.4800

R.S = P (A) P (B)

   = 0.7000 x 0.6000

   = 0.4200

L.S =/ R.S

The events of the residents of a household own 2 cars and income over $25,000 a year are not statistically dependent.

3b)

We have to prove P (A and B) = 0

L.S = P (A and B)

   = 0.4800

   =/ R.S = 0

The events of the residents of a household own 2 cars and income over $25,000 a year are not mutually exclusive.

3c)

We have to prove P (A or B) = 1

L.S = P (A or B)

   = P (A) + P (B) – P (A and B)

   = 0.7000 + 0.6000 – 0.4800

   = 0.8200 =/ R.S =1

The events of the residents of a household own 2 cars and income over $25,000 a year are not collectively exhaustive.

4i)

Let A be the number of student who did well on the Midterm.

Let A’ be the number of student who did poorly on the Midterm.