Answer: 135 days
Step-by-step explanation:
Since the amount of time it takes her to arrive is normally distributed, then according to the central limit theorem,
z = (x - µ)/σ
Where
x = sample mean
µ = population mean
σ = standard deviation
From the information given,
µ = 21 minutes
σ = 3.5 minutes
the probability that her commute would be between 19 and 26 minutes is expressed as
P(19 ≤ x ≤ 26)
For (19 ≤ x),
z = (19 - 21)/3.5 = - 0.57
Looking at the normal distribution table, the probability corresponding to the z score is 0.28
For (x ≤ 26),
z = (26 - 21)/3.5 = 1.43
Looking at the normal distribution table, the probability corresponding to the z score is 0.92
Therefore,
P(19 ≤ x ≤ 26) = 0.92 - 28 = 0.64
The number of times that her commute would be between 19 and 26 minutes is
0.64 × 211 = 135 days
I did not catch well, but i think you already got your answers. Let me explain. For the first part you got your notation right: for 0.0045 the correct scientific notation is 4.5 x 10^-3. Now the second part, the answer would be the first one, the notation that you are giving is the one who corresponds to <span>4.5 x 10^-2, the first option you have. Hope it helps</span>
3x and 2x are alike terms, as they have the same variable
