Answer:
Step-by-step explanation:
let one no. be 'x'.
the other no. is (x+2)
therefore the eq. is:
x+x+2= -68
2x+2= -68
2x = -68-2
= -70
x= -70/2
= -35
one number is -35
other number is (x+2) = -35 + 2
= -33
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:
-49x - 18 is the final answer!