Correct answer = C
"Common Probability Distributions," Richard A. Defusco, Dennis W. McLeavey, Jerald E. Pinto, and David E. Runkel
2008 Modular Level I, Vol. 1, pp. 391-392
Study Session 3-9-g
construct and interpret a confidence interval for a normally distributed random variable, and determine the probability that a normally distributed random variable lies inside a given confidence interval
Given that sales are normally distributed, the mean is centered in the interval.
Mean = ($230,000 + 480,000) / 2 = $355,000
An interval including 99% of the observations extends three standard deviations either side of the mean. The standard deviation of daily sales = ($355,000 - 230,000) / 3 = $41,667.
[此贴子已经被管理员于2008-5-17 18:24:35编辑过] | 
发表于 2008-5-30 00:50
| 