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:
Step-by-step explanation:
5.2
Answer: x<17.5
Step-by-step explanation:
Subtract from both sides: x+2.5-2.5<20-2.5
Simplify the arithmetic: x<20-2.5
Simplify the arithmetic: x<17.5
Hope it helps!
Answer:
-72
Step-by-step explanation:
-32 + (2-6)(10).
PEMDAS
parentheses first
-32 + -4*10
Then multiply
-32 -40
Then subtract
-72
Answer:
There are 12 pentapods and 8 Tripods, which in total add up to 84 feet.
Step-by-step explanation:
Given that both the Tripods and the Pentapods have, at least, 3 feet (the Pentapods have 5), and that in total between both groups they add 20 heads and 84 feet, the following logical reasoning can be made:
If there are 20 heads, there are 20 Martians in all. Each of them has, at least, 3 feet, with which in principle the 20 Martians would add up to a total of 60 feet (20 x 3). Therefore, there is a surplus of 24 feet (84 - 60).
If the Pentapods have 2 feet more than the Tripods, the number of Pentapods in the total Martians is determined by that difference. Thus, if there are 24 feet left, there are 12 Pentapods (24/2).
Therefore, in the group of Martians there are 12 pentapods (12 x 5 = 60) and 8 Tripods (8 x 3 = 24), which in total add up to 84 feet (60 + 24).
