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%
Answer:
Verified
Step-by-step explanation:
Use
,
and 
LHS=
=RHS
You will see a tiny picture up top of the question and draw it out and added then work
Answer:
B) 8 and 24.
Step-by-step explanation:
Just by looking at the answer choices, since one number must be three times the other, we can determine that the correct answer is B.
Regardless, let's work this out mathematically. Let the first number be <em>a</em> and the second number be <em>b</em>.
Their difference is 16. Hence:

The first number is three times the second number. So:

Substitute:

Solve for <em>b</em>. Subtract:

And divide both sides by two:

So, the second number is 8.
And since the first number is three times the second, the first number is 24.
Our answer is B as expected.