Question

The marks obtain by 10 students are 25 30 21 55 47 10 15 17 45 35. What is the probability that a student selected at random has marks more than the average marks

Answer 1

0.4

Explanation:

Average: sum/10

(25+30+21+55+47+10+15+17+45+35)/10

= 300/10 = 30

More than 30: 55, 47, 45, 35

Probability = 4/10 = 0.4

Answer 2

Answer: Pr (> average score)

= 2/5

Explanation:

Pr (> average score)=

Step 1: find the average score

Average score = sum of all scores/ number of scores

=300/10 = 30

Step2: select all scores greater than the average score: 55, 47,45 and 35

Pr = no of expected outcomes/ total no of outcomes

=4/10, in simplest form =2/5