Answer:
7.64% probability that they spend less than $160 on back-to-college electronics
Step-by-step explanation:
Problems of normally distributed samples can be 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:

Probability that they spend less than $160 on back-to-college electronics
This is the pvalue of Z when X = 160. So



has a pvalue of 0.0763
7.64% probability that they spend less than $160 on back-to-college electronics
If segment AB is perpendicular to segment CD, then a right angle (90°) is formed.
7x + 27 = 90
7x = 63
x = 9
Since it starts with 2 envelopes, subtract 2 from 17 to get how many and in all 3 packs.
17 - 2 = 15
Now, we divide that number by 3 to get how many are in each envelope.
15 / 3 = 5
There are 5 envelopes in each pack.
Answer: x = 1
Step-by-step explanation: In short, 0 is the only number such that for any number x, x + 0 = x. ... Well, it's the only number which can be multiplied by any other number without changing that other number. In short, the multiplicative identity is the number 1, because for any other number x, 1*x = x.