Answer:
(2,2)
Step-by-step explanation:
Answer:
1) 6+4x and 5+3x. 2) 3+6x and 10+2x. 3) 15+4x and 2+3x
Step-by-step explanation:
finding area is just multiplying the sides so find numbers that multiply to make 30 and 12
Now, there are 365 (excluding leap years) in a year, so, 275 days is not even a year, but is 275/365 of a year, or 55/73 of a year.
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.