Answer:
The percentage of students who scored below 620 is 93.32%.
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 question, we have that:

Percentage of students who scored below 620:
This is the pvalue of Z when X = 620. So



has a pvalue of 0.9332
The percentage of students who scored below 620 is 93.32%.
Look at the coefficient of x², ignore the positive or negative sign. The larger the coefficient, the narrower the graph.
in this case, the coefficients are -2, -1/2, -4, and 1/7
ignore the positive or negative sign, 4 is the largest number, so y=-4x² is the narrowest.
Note: the positive/negative sign tells you whether the graph opens upward or downward. It doesn't determine the width of the graph.
Answer:
3 • (2xy - 7) • (xy + 2)
Step-by-step explanation:
(((2•3x2) • y2) - 9xy) - 42
6x2y2 - 9xy - 42 = 3 • (2x2y2 - 3xy - 14)
Answer:
I think it would be 6800 square in because you just have to multiply 16 by 425.... Sorry if it is wrong
Step-by-step explanation:
It would be 3 times the sum of x and seven plus 10. This is because first you would would add 7+x (7x) and multiply it by 3. And then add on 10.