The mistake is in step 3:
I: −2m =−12 − 2n
II: 2m = 8 + 8n
the student set both right sides of the equations equal (−12 − 2n = 8 + 8n), but the left sides aren't equal: first equation has -2m, second has +2m so the signs of one of the equations must be inverted first
Answer:
The travel time that separates the top 2.5% of the travel times from the rest is of 91.76 seconds.
Step-by-step explanation:
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score 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 p-value, we get the probability that the value of the measure is greater than X.
Mean of 80 seconds and a standard deviation of 6 seconds.
This means that 
What travel time separates the top 2.5% of the travel times from the rest?
This is the 100 - 2.5 = 97.5th percentile, which is X when Z has a p-value of 0.975, so X when Z = 1.96.




The travel time that separates the top 2.5% of the travel times from the rest is of 91.76 seconds.
Answer:
Grapes=19.51
Step-by-step explanation:
Apples=$2.19 per pound
Grapes=$2.60 per pound
Apples+Grapes=20 pounds
A+G=20
A=20-G
Equation is
PaA+PgG=35.80
2.19A+2.60G=35.80
2.19(20-G)+2.60G=35.80
43.8-2.19G+2.60G=35.80
43.8-0.41G=35.80
-0.41G=35.80-43.8
-0.41G=-8
Divide both sides by 0.41
G=19.51 pounds
Recall
A=20-G
A=20-19.51
A=0.49 pounds
Answer:
24
Step-by-step explanation:
x (5-y)
Let x=6,and y=1
6(5-1)
PEMDAS says parentheses first
6(4)
24