When you write a numerical expression how can you show which operation to do it first?
1 answer:
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Answer:
Weights of at least 340.1 are in the highest 20%.
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:
a. Highest 20 percent
At least X
100-20 = 80
So X is the 80th percentile, which is X when Z has a pvalue of 0.8. So X when Z = 0.842.
Weights of at least 340.1 are in the highest 20%.
Answer:
(6, - 4 )
Step-by-step explanation:
Given the 2 equations
-
y = 3 → (1)
x -
= 12 → (2)
Multiply (1) by 8 and (2) by 6 to clear the fractions
2x - 3y = 24 → (3)
10x - 3y = 72 → (4)
Rearrange (3) expressing - 3y in terms of x by subtracting 2x from both sides
- 3y = 24 - 2x
Substitute 3y = 24 - 2x into (4)
10x + 24 - 2x = 72, that is
8x + 24 = 72 ( subtract 24 from both sides )
8x = 48 ( divide both sides by 8 )
x = 6
Substitute x = 6 in either (3) or (4) and solve for y
Substituting in (3)
2(6) - 3y = 24
12 - 3y = 24 ( subtract 12 from both sides )
- 3y = 12 ( divide both sides by - 3 )
y = - 4
Solution is (6, - 4 )