1.Find the sample mean of transportation cost incurred by the students of the NSU. Also,

calculate the standard deviation transportation cost incurred by the students of the NSU?

(10)

Transportation cost (in taka) Frequencies

0-30 50

31-61 160

62-92 100

93-123 90

124-154 60

2. In a conference the session on history and culture was attended by 40% of the delegates at

noon, while the session on tourism and sports was attended by 50% at evening. If attendance

at these sessions are statistically independent, what is the probability that a randomly chosen

delegate attended at least one of these sessions? (5)

3. The following table are showing the probabilities for Television Viewing and Income Level.

Find the Conditional Probabilities of Middle-Income Level, Given Occasional Viewing

Frequencies? (5)

Viewing Frequency High Income Middle Income Low Income Totals

Regular 0.06 0.14 0.13 0.33

Occasional 0.12 0.09 0.14 0.35

Never 0.10 0.09 0.13 0.32

Totals 0.28 0.32 0.40 1.00

4. A publisher sends advertising materials for an Economics text to 65% of all professors

teaching the appropriate Economics course. 35% percent of the professors who received this

material adopted the book, as did 10% of the professors who did not receive the material.

What is the probability that a professor who adopts the book has received the advertising

material? [Hints: Apply Bayes' Theorem].