709
Q:

# A problem is given to three students whose chances of solving it are 1/2, 1/3 and 1/4 respectively. What is the probability that the problem will be solved?

 A) 1/4 B) 1/2 C) 3/4 D) 7/12

Explanation:

Let A, B, C be the respective events of solving the problem and  be the respective events of not solving the problem. Then A, B, C are independent event

are independent events

Now,  P(A) = 1/2 , P(B) = 1/3 and P(C)=1/4

$∴$ P( none  solves the problem) = P(not A) and (not B) and (not C)

= $PA∩B∩C$

= $PAPBPC$

=  $12×23×34$

= $14$

Hence, P(the problem will be solved) = 1 - P(none solves the problem)

= $1-14$= 3/4

Q:

If the standard deviation of a population is 6.5, what would be the population variance?

 A) 40.25 B) 42.25 C) 18.25 D) 13

Explanation:

0 74
Q:

The mean of a distribution is 21 and the standard deviation is 7. What is the value of the coefficient variation?

 A) 16.66% B) 66.66% C) 33.33% D) 100%

Explanation:

0 67
Q:

X attempts 94 questions and gets 141 marks. If for every correct answer 4 marks is given, and for every wrong answer 1 mark is deducted, then the number of questions wrongly answered by X is __.

 A) 45 B) 47 C) 57 D) 40

Explanation:

4 142
Q:

Which of the following questions is a statistical question?

 A) Where do the professional sports leagues play? B) How many professional sports leagues are there? C) How many hours do the student-athletes at your school spend each week training for a sports league? D) How many hours of professional training took place over the weekend?

Answer & Explanation Answer: B) How many professional sports leagues are there?

Explanation:

A statistical question is a question that can be answered by collecting data that vary.

In the given options, How many professional sports leagues are there? is a statistical question. Here to answer this question, we have to collect data from the sources.

0 101
Q:

What is the median of the following list of numbers

55, 53, 56, 59, 61, 69, and 31 ?

 A) 55 B) 56 C) 59 D) 61

Explanation:

0 176
Q:

The second statement is the ____ of the first.

 A) Converse B) Inverse C) Contrapositive D) Contradiction

Explanation:

1 278
Q:

If the standard deviation of a population is 4.5, what would be the population variance?

 A) 20.25 B) 20 C) 9 D) 18

Explanation:

3 238
Q:

The mean of a distribution is 20 and the standard deviation is 4. What is the value of the coefficient variation?

 A) 10% B) 20% C) 40% D) 60%