A) Daily sales of petrol from the Nabua service station are normally distributed with

Question

Mean6300Landthe standard deviation 400L.
(i) If a daily sale is selected at random, find the probability that it is less than 6200L.
(ii) If petrol sales are sampled for 40 days, and the mean is calculated, find the

Answer 1

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http://davidmlane.com/normal.html

Answer 2

i)

P(X < 6200)
P(Z < 6200-6300/400)
P(Z < - 0.25) = 0.4013

The probably of sales being less than 6200L is 40.13%

ii) Question is not complete, so I cannot answer it.