Answer:
X = 31.5
Step-by-step explanation:
X / 1.5 = 21
X = 21 * 1.5
Answer:
P(E or F)=P(E)+P(F)=0.41+0.47=0.88
Answer: 69,960 divide 132,000 by 53% you get 69.960
Step-by-step explanation:
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:
