Answer:
see explanation
Step-by-step explanation:
The translation represented by
interprets as a shift of 1 unit to the right ( add 1 to x- coordinate ) and a
shift of 4 units down ( subtract 4 from the y- coordinate ), then
(1, 4 ) → (1 + 1, 4 - 4 ) → (2, 0 )
(4, 4 ) → (4 + 1, 4 - 4 ) → (5, 0 )
(6, 2 ) → (6 + 1, 2 - 4 ) → (7, - 2 )
(1, 2 ) → (1 + 1, 2 - 4 ) → (2, - 2 )
Answer:
The top 20% of the students will score at least 2.1 points above the mean.
Step-by-step explanation:
When the distribution is normal, we use 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.
The mean of a certain test is 14 and the standard deviation is 2.5.
This means that
The top 20% of the students will score how many points above the mean
Their score is the 100 - 20 = 80th percentile, which is X when Z has a pvalue of 0.8. So X when Z = 0.84.
Their score is:
16.1 - 14 = 2.1
The top 20% of the students will score at least 2.1 points above the mean.