QCEVault

Discrete random variables — Question 327

Original QCE Vault practice · 6 marks

Q327 · Practice questionTechnology-activeComplex unfamiliar6 marks

QUESTION 327 (6 marks)

The setup time for one independently prepared escape-room station is normally distributed with mean 1818 minutes and standard deviation 33 minutes. A station is ready on time if setup takes no more than 2121 minutes. Ten stations are prepared independently.
a)
Determine the probability that one station is ready on time, to four decimal places.
[2 marks]
b)
Determine the probability that at least nine stations are ready on time, to four decimal places.
[3 marks]
c)
Determine the expected number that are late, to two decimal places.
[1 mark]
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