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.
The values of a and b equals 10
Answer:
23m-18
Step-by-step explanation:
2(7m−5)+(−8+9m)
Remove parenthesis
2(7m-5)-8+9m
expand
14m-10
14m-10-8+9
simplify
23m-18
Ask me for more questions brainliest please.
Answer:
0.25 k miles
Step-by-step explanation:
15 minutes =1/4 of an hour
Distance= speed*time= k (1/4)= (1/4) k= 0.25 k miles