The mean SAT score in mathematics is 554. The standard deviation of these scores is 39. A special preparation course claims that
1 answer:
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Answer:
The middle 92% of all heights fall between 64.4 inches and 74.2 inches.
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:
Between what two values does that middle 92% of all heights fall?
The middle 92% falls from X when Z has a pvalue of 0.5 - 0.92/2 = 0.04 to X when Z has a pvalue of 0.5 + 0.92/2 = 0.96. So from the 4th percentile to the 96th percentile.
4th percentile
X when
96th percentile
X when
The middle 92% of all heights fall between 64.4 inches and 74.2 inches.
Given:
In parallelogram PQRS, .
To find:
The value of x.
Solution:
In a parallelogram, the consecutive interior angles are supplementary angles.
In parallelogram PQRS,
(Supplementary angles)
Subtracting 20 from both sides, we get
Divide both sides by 8.
Therefore, the correct option is C.