1. P (A or B) = P (A ∪ B) = P(A) + P(B) – P (A ∩ B) applies When two events are mutually exclusive
A. A ∩
B. B = φ
C. Both (a) and (b)
D. None of the above
2. Under the normal curve µ +– 1 σ covers
A. 95.5% area
B. 68% area
C. 86% area
D. 99.7% area
3. Normal distribution has ………… mode
A. Numerous
B. Two
C. One
D. None of the above
4. What is the shape of normal curve?
A. Bell shaped
B. Positively skewed
C. Negatively skewed
D. None of the above
5. Find the area under the normal curve for Z = 1.54
A. 0.378
B. 0.4528
C. 0.4382
D. 0.4120
6. 15,000 students appeared for an examination. The mean marks were 49 and the standard deviation of marks was 6. Assuming the marks to be normally distributed, what proportion of students scored more than 55 marks?
A. 17.57%
B. 15.87%
C. 57.58%
D. 25.15%
7. Find the area under normal curve for Z = 1.46
A. 0.4279
B. 0.4729
C. 0.48
D. 0.465
8. 15,000 students appeared for an examination. The mean marks were 49 and the standard deviation of marks was 6. Assuming the marks to be normally distributed Grade A is to be given to students scoring more than 70 marks, what proportion of students will receive grade A?
A. 0.15%
B. 27%
C. 20%
D. 0.02%
9. The main purpose for using a normal distribution is
A. To fill a distribution of measurement for same sample data
B. To approximate the distributions like Binomial, Poisson etc.
C. To fit sampling distribution of various statistics like mean or variance etc.
D. All of the above
10. In a training programme to develop marketing skills of marketing personnel of a company, the participants indicate that the mean time on the programme is 500 hours and that this normally distributed random variable has a standard deviation of 100 hours. Find out the probability that a participant selected at random will take fewer than 570 hours to complete the programme?
A. 79.25%
B. 83%
C. 75.8%
D. 57.23%
11. It is a single number which is used as an estimate of the unknown population parameter.
A. Point estimation
B. Standard error
C. Non-point estimation
D. Interval estimation
12. If E(T) = θ + a (θ), then the difference a (θ) = E(T) θ is known as
A. Interval
B. Point
C. Bias
D. None of the above
13. If µ denotes the population mean, then we intend to make a guess about it on the basis of a random sample. This is known as
A. Approximate
B. Estimation
C. Guess
D. None of the above
14. The bias is known to be positive if
A. a (θ) < 0
B. a (θ) > 0
C. Both (a) and (b)
D. Neither (a) nor (b)
15. A statistic T is called as an ……………. estimator of θ if it has the minimum standard error among all the estimators of θ for a fixed sample size n.
A. Effective
B. Efficient
C. Sufficient
D. None of the above
16. Estimates that are commonly used for
A. Estimating Population Mean
B. Estimating Population Proportion
C. Both (a) and (b)
D. Neither (a) nor (b)
17. A statistic T is known to be a …………… estimator of θ if T contains sufficient information about θ so that we do not have to look for any other estimator of θ
A. Complete
B. Sufficient
C. Efficient
D. None of the above
18. It is denoted by S.E. (T), may be defined as the standard deviation of T as obtained from the sampling distribution of T.
A. Standard error
B. Confidence interval
C. Estimation
D. None of the above
19. An interval estimate would always be specified by ………… values.
A. One
B. Three
C. Two
D. Four
20. It may be defined as estimating an interval to which the unknown parameter θ may belong, in all likelihood.
A. Point estimation
B. Scale estimation
C. Interval estimation
D. None of the above