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
Answer:
Each plane cuts the other two in a line and they form a prismatic surface. ... The second and third planes are coincident and the first is cuting them, therefore the three planes intersect in a line.
Step-by-step explanation:
The only thing you can do with this expression is to factor a 5 out of the two terms: we have

------------------------------------------------------------------
Question
------------------------------------------------------------------

------------------------------------------------------------------
Split the fraction on the left
------------------------------------------------------------------

------------------------------------------------------------------
Take away h/5 from both sides
------------------------------------------------------------------

------------------------------------------------------------------
Change the denominator to be the same
------------------------------------------------------------------

------------------------------------------------------------------
Put it into single fraction
------------------------------------------------------------------

-------------------------------------------------------------------
Rearrange (This step may not be necessary)
------------------------------------------------------------------

Answer:
20
23 is between 20 and 30, but it's closer to 20. So 23 is rounded down to 20.