Answer:
A
Step-by-step explanation:
Answer:
Harry = 10 toys
Mark = 20 toys
Sue = 20 toys
Step-by-step explanation:
H + M + S = 50
H = M - 10
S = 2H
Harry = 10 toys
Mark = 20 toys
Sue = 20 toys
Answer:
A. x = 5
Step-by-step explanation:
3x + 9 = 24
→ Minus 9 from both sides
3x = 15
→ Divide both sides by 3
x = 5
Answer:
6.18% of the class has an exam score of A- or higher.
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.
In this question, we have that:

What percentage of the class has an exam score of A- or higher (defined as at least 90)?
This is 1 subtracted by the pvalue of Z when X = 90. So



has a pvalue of 0.9382
1 - 0.9382 = 0.0618
6.18% of the class has an exam score of A- or higher.