…………………………………………….not really sure about the last question
Answer:

And we can assume a normal distribution and then we can solve the problem with the z score formula given by:

And replacing we got:


We can find the probability of interest using the normal standard table and with the following difference:

Step-by-step explanation:
Let X the random variable who represent the expense and we assume the following parameters:

And for this case we want to find the percent of his expense between 38.6 and 57.8 so we want this probability:

And we can assume a normal distribution and then we can solve the problem with the z score formula given by:

And replacing we got:


We can find the probability of interest using the normal standard table and with the following difference:

Answer:
-16
Step-by-step explanation:
Anything written in the form of a(b) or (b)a means a × b:
(-4)4 means -4 × 4 which is -16 (a positive and a negative multiplied together make a negative).
Hope this helps!
X: -2| -1| 0| 1| 2|
y: 1.25| 2.5| 5| 10| 20|
45 multiply 1/2 and 90 put it in the calculator 90 times 0.5