Solve the system of equations 4x - 5y = –6 and -6x + 7y = 12 by combining the equations
1 answer:
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Answer:
A. 16%
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:
Which of the following gives the probability that a randomly selected woman has a height of greater than 68 inches?
This is 1 subtracted by the pvalue of Z when X = 68. So
has a pvalue of 0.84.
1 - 0.84 = 0.16
So the correct answer is:
A. 16%
Answer:
And using a calculator, excel or the normal standard table we have that:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the weigths of a population, and for this case we know the distribution for X is given by:
Where and
Since the distribution for X is normal then we know that the distribution for the sample mean is given by:
We can find the probability required with the following z score formula:
And replacing we got:
And using a calculator, excel or the normal standard table we have that: