Answer:
A
Step-by-step explanation:
Answer:
62.17% probability that a randomly selected exam will require more than 15 minutes to grade
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 randomly selected exam will require more than 15 minutes to grade
This is 1 subtracted by the pvalue of Z when X = 15. So



has a pvalue of 0.3783.
1 - 0.3783 = 0.6217
62.17% probability that a randomly selected exam will require more than 15 minutes to grade
Answer:
A 21 /169
B independent
Step-by-step explanation:
The total number of candies is 7+3+3 = 13
P( 1st red) = red/total = 7/13
Since the candy is put back there are still 13 candies in the dish
P(2nd green) = green/total = 3/13
P( red, then green) = P( 1st red) * P(2nd green)
= 7/13* 3/13 = 21/169
The events are independent since the candies are put back
Answer:
20
Step-by-step explanation:
cause when you do 3=4 equals 4 then multiply 5 then you have 20