A study of long-distance phone calls made from General Electric Corporate Headquarters in Fairfield, Connecticut, revealed the length of the calls, in minutes, follows the normal probability distribution. The mean length of time per call was 4.2 minutes and the standard deviation was 0.40 minutes. What is the probability that calls last between 4.2 and 4.9 minutes

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

f(x) is going down by 4

step-by-step explanation:

(its either that or its going left by 4)

on monday rodney ate 1/4th of the sandwich = 3/12

on tuesday he ate 1/3rd of the sandwich = 4/12

therefore in total he has eaten = 3/12 + 4/12 = 7/12

thus we can say that he has eaten 7/12 of the sandwich on monday and tuesday alltogether.

happy to

pls mark as brainliest.