John drives to work each morning, and the trip takes an average of µ = 38 minutes. The distribution of driving times is approximately normal with a standard deviation of σ = 5 minutes. For a randomly selected morning, what is the probability that John’s drive to work will take between 36 and 40 minutes?​

Respuesta :

Answer: the probability that John’s drive to work will take between 36 and 40 minutes is 0.32

Step-by-step explanation:

Since the distribution of driving times is approximately normal, we would apply the formula for normal distribution which is expressed as

z = (x - µ)/σ

Where

x = driving times.

µ = mean time

σ = standard deviation

From the information given,

µ = 38 minutes

σ = 5 minutes

The probability that John’s drive to work will take between 36 and 40 minutes is expressed as

P(36 ≤ x ≤ 40)

For x = 36,

z = (36 - 38)/5 = - 0.4

Looking at the normal distribution table, the probability corresponding to the z score is 0.34

For x = 40,

z = (40 - 38)/5 = 0.4

Looking at the normal distribution table, the probability corresponding to the z score is 0.66

Therefore,

P(36 ≤ x ≤ 40) = 0.66 - 0.34 = 0.32

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