DevoreStat9 4.5.081.S.
Sales delay is the elapsed time between the manufacture of a product and its sale. According to an article it is quite common for investigators to model sales delay using a lognormal distribution. For a particular product, the article proposes this distribution with parameter values
𝜇 = 2.06
and
𝜎2 = 0.05
(here the unit for delay is months).
(a)
What are the variance (in months2) and standard deviation (in months) of delay time? (Round your answers to two decimal places.)
variance months2standard deviation months
(b)
What is the probability that delay time exceeds 12 months? (Round your answer to four decimal places.)
(c)
What is the probability that delay time is within one standard deviation of its mean value? (Round your answer to four decimal places.)
(d)
What is the median (in months) of the delay time distribution? (Round your answer to two decimal places.)
months
(e)
What is the 99th percentile (in months) of the delay time distribution? (Round your answer to two decimal places.)
months
(f)
Among 10 randomly selected such items, how many would you expect to have a delay time exceeding 5 months? (Round your answer to three decimal places.)
items