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

Answer:   C) 3/4



Explanation:

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

A, B, C are independent events

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

 PA=12, PB=23, PC= 34

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

                  = PABC 

                  = PAPBPC          A, B, C are Independent                       

                  =  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
 
Answer & Explanation Answer: B) 42.25

Explanation:
Report Error

View Answer Report Error Discuss

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%
 
Answer & Explanation Answer: C) 33.33%

Explanation:
Report Error

View Answer Report Error Discuss

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
 
Answer & Explanation Answer: B) 47

Explanation:
Report Error

View Answer Report Error Discuss

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.

 

Report Error

View Answer Report Error Discuss

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
 
Answer & Explanation Answer: B) 56

Explanation:
Report Error

View Answer Report Error Discuss

0 176
Q:

The second statement is the ____ of the first.

 

1.  P  Q2.  ~Q  ~P

 

A) Converse B) Inverse
C) Contrapositive D) Contradiction
 
Answer & Explanation Answer: C) Contrapositive

Explanation:
Report Error

View Answer Report Error Discuss

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
 
Answer & Explanation Answer: A) 20.25

Explanation:
Report Error

View Answer Report Error Discuss

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%
 
Answer & Explanation Answer: B) 20%

Explanation:
Report Error

View Answer Report Error Discuss

4 220