Answer:
The probability that a call last between 4.2 and 4.9 minutes is 0.4599
Step-by-step explanation:
Let X be the length in minutes of a random phone call. X is a normal distribution with mean λ=4.2 and standard deviation σ=0.4. We want to know P(4.2 < X < 4.9). In order to make computations, we will use W, the standarization of X, given by the following formula

We will use
, the cummulative distribution function of W. The values of
are well known and the can be found in the attached file

We conclude that the probability that a call last between 4.2 and 4.9 minutes is 0.4599
Answer:
3.5
Step-by-step explanation:
Test Scores
1, 1, 2, 3, 3, 4, 4, 5, 5, 5
median(middle #)
(3+4)/2 = 7/2 = 3.5
The answer is 55 and 25 (25)x2=50, 50+5=(55), 55+25=80.
The probability of choosing Joey first is 1/12 .
If that happens, the probability of choosing Chloe next is 1/11 .
Then, the probability of choosing Zoe after that is 1/10 .
The probability of all these things happening is
(1/12) x (1/11) x (1/10)
= 1/1320 = 0.00076 = 0.076 percent
Answer:
c = 12
Step-by-step explanation:
3(c - 4) = 4(c - 6)
Use the distributive property on each side.
3c - 12 = 4c - 24
Now you need the terms with c on the left side and the numbers on the right side. Subtract 4c from both sides. Add 12 to both sides.
3c - 4c - 12 + 12 = 4c - 4c - 24 + 12
Combine like terms on each side.
-c = -12
Multiply both sides by -1.
c = 12