Questions Douilles
If a positively skewed distribution has a median of 50, which of the following statement is TRUE? A) Mean is greater than 50 B) Mean is less than 50 C) Mean is equal to 50 D) Mode is greater than 50
A
About two independent events A and B, it is known that P(A | B) = 0.2 and P(B | A) = 0.5. Compute the probability P(A or B). A) 0.7 B) 0.2 C) 0.4 D) 0.6
D
If two events are collectively exhaustive, what is the probability that both occur at the same time? a) 0. b) 0.50. c) 1.00. d) Cannot be determined from the information given.
D
If two events are mutually exclusive, what is the probability that one or the other occurs? a) 0. b) 0.50. c) 1.00. d) Cannot be determined from the information given.
D
In a perfectly symmetrical bell-shaped "normal" distribution. a) the mean equals the median. b) the median equals the mode. c) the mean equals the mode. d) All the above.
D
Which is not true about binomial distribution? A) The probability of the event of interest must be constant from trial to trial. B) Each outcome is independent of the other. C) Each outcome may be classified as either "event of interest" or "not event of interest". D) The variable of interest is continuous.
D
Which of the measures given below is a measure of variability that is not influenced by outliers or extreme values? A) Range B) Standard Deviation C) First Quartile D) Interquartile Range
D
Which one of the following charts is the most suitable to identify the vital reasons? A) Bar Chart B) Histogram C) Pie Chart D) Pareto Chart
D
Which statement is TRUE? A) The mean and standard deviation of standard normal random variable Z is 1 and 0, respectively. B) The mean of a normal random variable is always larger than its standard deviation. C) The 10th percentile of a Z distribution has 10% of the Z-values lying above it. D) None of the above.
D
Data must be arranged either in ascending or descending order if you want to compute A) Mode B) Median C) Standard Deviation D) Average
B
Which one of the following is NOT TRUE about the binomial distribution? A) A binomial experiment consists of a sequence of n trials, where n is fixed in advance of the experiment. B) Each trial can result in at least two possible outcomes. C) The trials are independent, so that the outcome of a trial does not affect the outcome of any other trial. D) The probability of an outcome is constant from trial to trial.
B
Which one of the following is TRUE? A) Using sample information to draw conclusions information about population parameters is known as descriptive statistics. B) A sample statistic changes each time you try to measure it, but a population parameter remains fixed. C) A population parameter changes each time you try to measure it, but a sample statistic remains fixed across samples. D) The true value of a sample statistic can never be known but the true value of a population parameter can be known.
B
In a right-skewed distribution a) the median equals the mean. b) the median is less than the mean. c) the median is greater than the mean. d) none of the above.
B (mode is also less than median)
For a random variable that follows the normal distribution with a mean of 5 and a standard deviation of 2, which Excel function finds the probability that the random variable takes a value smaller than 2? a) = 1 - NORM.DIST(2,5,2,TRUE) b) = NORM.DIST(2,5,2,FALSE) c) = NORM.DIST(2,5,2,TRUE) d) = NORM.S.DIST(1.5,TRUE)
C
If two events are mutually exclusive and collectively exhaustive, what is the probability that one or the other occurs? a) 0. b) 0.50. c) 1.00. d) Cannot be determined from the information given.
C
Suppose that you are given two events E1, E2, their prior probabilities P(E1), P(E2) and another event S for which the probabilities P(S|E1) and P(S|E2) are known. Which one of the following conditions should hold to apply Bayes' Theorem for the calculation of P(S)? A) E1 and E2 are independent. B) E1 and E2 and S are independent. C) E1 and E2 are mutually exclusive. D) E1 and E2 and S are mutually exclusive and collectively exhaustive
C
When extreme values are present in a set of data, which of the following descriptive summary measures are most appropriate: a) coefficient of variation and range. b) mean and standard deviation. c) interquartile range and median. d) variance and interquartile range.
C
Which statement is FALSE? A) A continuous random variable can assume infinite number of possible values. B) Categorical variables cannot follow a continuous probability distribution. C) A continuous random variable X has a uniform distribution between 10 and 20 (inclusive), then the probability that X falls between 22 and 25 is 0.30. D) Since there is an infinite number of values a continuous random variable can assume, the probability of each individual value is virtually 0.
C
Which statement is FALSE? a) Collectively exhaustive events may occur at the same time. b) Mutually exclusive events may be also collectively exhaustive. c) The joint probability of independent events is always 0. d) None of the above.
C
A random variable follows a binomial distribution with 𝑛 = 5 and 𝑝 = 0.5. Which Excel function finds the probability that this random variable takes a value larger than 3? a) =BINOM.DIST(3,5,0.5,FALSE) b) =BINOM.DIST(4,5,0.5,TRUE) c) =1 - BINOM.DIST(3,5,0.5,FALSE) d) =1 - BINOM.DIST(3,5,0.5,TRUE)
D because always TRUE with BINOM
