211) Which of the following about the normal distribution is not true?
a) Theoretically, the mean, median, b) About 2/3 of the observations fall
and mode are the same. within ±1 standard deviation from
the mean.
c) It is a discrete probability distribution. d) Its parameters are the mean, μ , and
standard deviation, σ.
212) If a particular set of data is approximately normally distributed, we would find that
approximately :
a) 2 of every 3 observations would fall b) 4 of every 5 observations would fall
between ±1 standard deviation around the between ±1.28 standard deviations
mean. around the mean.
c) 19 of every 20 observations would fall d) All the above.
between ±2 standard deviations around the
mean.
213) As prices of basic commodities have increased over the past decade, the cost of attending a
four year university, where students seek their first college degree have been affected as
well. Data for the cost of books is listed below:
25 50 75 100 125 150 175 200 225 250
Data is approximately:
a) exponentially distributed. b) uniformly distributed.
c) normally distributed. d) none of the above.
61
, 214) You were told that the amount of time lapsed between consecutive trades on a foreign
stock exchange market followed a normal distribution with a mean of 15 seconds. You
were also told that the probability that the time lapsed between two consecutive trades to
fall between 16 to 17 seconds was 13%. The probability that the time lapsed between two
consecutive trades would fall below 13 seconds was 7%.
(I) what is the probability that the time lapsed between two consecutive trades will be
between 13 and 16 seconds?
a) 0.90 b) 0.73
c) 0.53 d) 0.26
(II) The probability is 20% that the time lapsed will be shorter how many seconds?
a) 14 seconds b) 10 seconds
c) 17 seconds d) 6 seconds
(III) The middle 86% of the time lapsed will fall between which two numbers?
a) 15 seconds and 20 seconds b) 10 seconds and 17 seconds
c) 13 second and 20 seconds d) 13 seconds and 17 seconds
62