Answer:
0
Step-by-step explanation:
x + y = 3
y = 3
=> x + 3 = 3
=> x = 3 - 3
=> x = 0
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
Std dev = sqrt of variance
hence variance would be 17^2= 289
Area of triangle = 1/2 x base x height
so old triangle we have 1/2 x b x h = 48
new triangle has base 3 times as long and height is half as long
so we would get:
1/2 x (3B) x (1/2H) = area
rewrite as 1/2 x 3/2 x b x H = area
divide by original are os 1/2 x b x h and you end up with 3/2
so new area = 3/2 x old area
new area = 3/2 * 48 = 72 square inches
Answer:
522
Step-by-step explanation: