Answer:
-2/3= x
Step-by-step explanation:
<u><em>square all the terms on both sides to get rid of the radicals:</em></u>
<u><em>exponent 2 and the radical cancel each other:</em></u>
1 + 1 - x = 2x + 4
2 - x = 2x + 4
<u><em>like terms on each side ( when you move one term tp the other side, it changes its sign ):</em></u>
2-x = 2x+4
2-4 = +x +2x
-2 = 3x
<u><em>now to keep the x alone, divide both sides by 3:</em></u>
-2/3 = 3x/3
-2/3= x
Answer:
74.22% probability that a family of four will spend more than $400.
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:
What is the probability that a family of four will spend more than $400?
This is 1 subtracted by the pvalue of Z when X = 400. So
has a pvalue of 0.2578.
So there is a 1-0.2578 = 0.7422 = 74.22% probability that a family of four will spend more than $400.