Explanation:
This looks like an essay question with no right answer.
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There are two "special" right triangles:
isosceles 45°-45°-90° triangle with sides in the ratios 1 : 1 : √2
30°-60°-90° triangle with sides in the ratios 1 : √3 : 2
These side lengths give rise to the trigonometric ratios shown below for angles with 30°, 45°, or 60° as reference angles.
Answer:
95.15%
Step-by-step explanation:
We have that the mean (m) is equal to 20, the standard deviation (sd) 3
They ask us for P (x <25)
For this, the first thing is to calculate z, which is given by the following equation:
z = (x - m) / sd
We have all these values, replacing we have:
z = (25 - 20) / (3)
z = 1.66
With the normal distribution table (attached), we have that at that value, the probability is:
P (z <1.66) = 0.9515
Which means that the probability that it arrives before 25 minutes is 95.15%
