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[問題] maths and stat (normal distribution)

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maths and stat (normal distribution)

Oxfam Trailwalker is  a marathon game covering many country parks in Hong Kong . Participants have to complete 100km of hiking within 48hours in order to get a certificate. Suppose in year2000, the finishing time of 3600 participant followed a normal distribution with a mean of 30.27 hours and a variance of 28.95 hours^2.

(A)"super Trailwalkers" are those participants who complete the game within 18 hours. Approximately how many "super Trailwalkers were there in year 2000?

(b)What proportion of participant could not get the certificate?

(C)Suppose Sammy finished the race in 36 hours. How manty standard deviations was she faster or slower than the mean?

(d)What were the upper and lower boundaries of the finishing times that covered the central 82% of the participants?
   

TOP

n = 3600
mu = 30.27
var = 28.95

你明白normal distribution公式(Z value)
明白睇圖自然可以代入數字

不明白題目意思?

TOP

補充樓上
28.95係standard deviation

TOP

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