Methods2026 NHT Exam 2 Section A · Q3CAS active1 mark

Normal probability via standard normal

Assume that the time, in minutes, it takes for a particular student to travel to school is a normal random variable with mean 15 and variance 4.

Let $Z$ be a standard normal random variable.

The probability that it takes the student more than 20 minutes to travel to school is equal to

1 mark

\Pr(Z < 1.25)

\Pr(Z < 2.5)

1 - \Pr(Z < 1.25)

1 - \Pr(Z < 2.5)

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