First introduce the following notations:
Answer:
The average monthly expenditure is 1,155.35 $.
Step-by-step explanation:
The average of any sequency is given by the sum of it's individual parts divided by the number of parts it has. So in this case the average of monthly expenditure will be the sum of all individual expenditures divided by the number of months. The question can be solved like this:
average = (March+ April + May + June + July+ August)/6
average = (1,249.59 + 1,365.38 + 1,024.3 + 1,100.4 + 992,4 + 1,200.02)/6
average = 1,155.35 $
Answer:
22.29% probability that both of them scored above a 1520
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

The first step to solve the question is find the probability that a student has of scoring above 1520, which is 1 subtracted by the pvalue of Z when X = 1520.
So



has a pvalue of 0.5279
1 - 0.5279 = 0.4721
Each students has a 0.4721 probability of scoring above 1520.
What is the probability that both of them scored above a 1520?
Each students has a 0.4721 probability of scoring above 1520. So

22.29% probability that both of them scored above a 1520
Answer:
more information would love to help
Step-by-step explanation:
The range is 30 to find the range u subtract the biggest from the smallest so 81-51=30 hope this helps