Answer:
y=2
Step-by-step explanation:
Answer:
B
Step-by-step explanation:
Answer:
The solution to this system is (4, 1/6).
Step-by-step explanation:
Please separate these two equations for clarity. I like to write them in column format:
2.5y + 3x = 27
5x – 2.5y = 5
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8x = 32, and x = 4.
Subbing 4 for x in the second equation yields 5(4) - 2.5y = 5.
Then 20 - 2.5y = 5, or 15 = 2.5y. Solving for y, we get y = 1/6.
The solution to this system is thus (4, 1/6).
Answer:
(B) The standard normal variable Z counts the number of standard deviations that the value of the normal random variable X is away from its mean
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.
Positive z-score: Above the mean
Negative z-score: Below the mean
All variables are continuous.
X can be positive or negative, just like Z
So the correct answer is:
(B) The standard normal variable Z counts the number of standard deviations that the value of the normal random variable X is away from its mean