Answer:
14.63% probability that a student scores between 82 and 90
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:

What is the probability that a student scores between 82 and 90?
This is the pvalue of Z when X = 90 subtracted by the pvalue of Z when X = 82. So
X = 90



has a pvalue of 0.9649
X = 82



has a pvalue of 0.8186
0.9649 - 0.8186 = 0.1463
14.63% probability that a student scores between 82 and 90
Answer:
276
Step-by-step explanation:
240+(240*.15) = 276
Answer:
The probability of hitting a single or a double is 1/5 or 20% or 20/100 or 0.2
Step-by-step explanation:
In probability, whenever we are to answer an ‘or’ question, we add up the probabilities involved.
The probability of hitting a single is 15%, that is same as 15/100 or just simply 0.15
The probability of hitting a double is 5%, that is simply 5/100 or just simply 0.05
The probability of hitting a single or a double = Probability of hitting a single + Probability of hitting a double = 0.15 + 0.05 = 0.20 or 20/100 or 1/5
A and D are true
good luck
I don't know what this is supposed to mean, but thanks for the free points! ;)