Answer:
The top 20% of the students will score at least 2.1 points above the mean.
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.
The mean of a certain test is 14 and the standard deviation is 2.5.
This means that 
The top 20% of the students will score how many points above the mean
Their score is the 100 - 20 = 80th percentile, which is X when Z has a pvalue of 0.8. So X when Z = 0.84.
Their score is:




16.1 - 14 = 2.1
The top 20% of the students will score at least 2.1 points above the mean.
Answer:
if the two bottles are 1 liter each then those two bottles would hold more juice because in total they would hold two liters of juice
Step-by-step explanation:
the 12 cans of 150 ml would hold a total of 1.8 liters which is less than 2 liters
It is already in its lowest form :P Unless you wan the decimal which is 0.061224489 ish
Problem 1
Answers:
Domain: 
Range: 
--------------------
Explanation:
The domain is the set of allowed x inputs of a function. The smallest x value we can use is x = -3 (note the very left-most point of the graph). The right-most point involves x = 5, but we can't actually use this x value due to the open hole. So that's why we don't have "or equal to" attached to the 5.
The range is the set of possible y outputs. The lowest we can go is y = -4, but we don't include this as part of the range. The largest y can get is y = 3. So the range is 
===========================================
Problem 2
Answers:
Domain: 
Range: 
--------------------
Explanation:
We use the same idea as in problem 1. Both endpoints are open holes, so we don't include them as part of the domain and range. For instance, we can't include x = 4 but we can get closer and closer to it. The same idea applies to the range as well.
===========================================
Problem 3
Answers:
Domain: 
Range: 
--------------------
Explanation:
The same idea applies as used earlier. This time we include both endpoints, so we have "or equal to" as part of each inequality sign.