Answer:
<u>The sum of their ages now is 13</u>
Step-by-step explanation:
Dally's age = x
Dilly's age = x - 7
In 4 years time Dilly will be half Dally’s age, therefore:
Dilly's age plus four equals to half of Dally’s age plus four,
replacing with the values and variables we know:
x - 7 + 4 = (x + 4) /2
x - 3 = (x + 4) /2
2x - 6 = x + 4 (Multiplying by 2 at both sides)
2x - x = 4 + 6 (Like terms)
x = 10 ⇒ x - 7 = 3
<u>The sum of their ages now is 13 (10 + 3)</u>
Answer:
The artist makes profits when n>8.18
that is when the number of necklaces exeeds 8.18
Step-by-step explanation:
Given
let the number of necklaces be n
booth rent= $135
The cost of materials for the necklaces = $4.5n
the selling price for all the necklaces =$12n
total expenses= booth rent+cost of material = $135+4.5n
profit = selling price -total expenses
12n > 135 + 4.50n
solving for n we have
12n=135 + 4.50n
12n+4.5n=135
16.5n=135
n=135/16.5
n=8.18
The artist makes profits when n>8.18
Answer:
Carl's ACT grade had a higher z-score, which means that he earned a better score with respect to his peers on the ACT test.
Step-by-step explanation:
Z-score
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.
On which exam did Carl earn a better score with respect to his peers?
On whichever exam he had the higher z-score.
SAT
Scored 730, mean 516, standard deviation 116. So
ACT
Scored 32, mean 21, standard deviation 5.3. So
Carl's ACT grade had a higher z-score, which means that he earned a better score with respect to his peers on the ACT test.
Answer:
The quadratic equation is f(x)=20x^{2} -400x +3000.
1. This number represents the amount of money it was sold for.
2. Vertex =(10,1000)
Step-by-step explanation:
This point represents the amount of money the computer was worth at its lowest point.
