Answer:
532
Step-by-step explanation:
The score that represents the top 20% = A score = 80%
Z score for 80% percentile = 0.842
We solve using the z score formula
z = (x-μ)/σ, where
x is the raw score = ??
μ is the population mean = 490
and σ is the population standard deviation = 50
Hence:
0.842 = x - 490/50
Cross Multiply
0.842 × 50 = x - 490
x = 0.842 × 50 + 490
x = 42.1 + 490
x = 532.1
Approximately = 532
Therefore, the test score = 532
Let the cost of a chicken be x and the cost of a duck, y, then
50x + 30y = 550 . . . (1)
44x + 36y = 532 . . . (2)
(1) x 6 ⇒ 300x + 180y = 3,300 . . . (3)
(2) x 5 ⇒ 220x + 180y = 2,660 . . . (4)
(3) - (4) ⇒ 80x = 640
⇒ x = 640 / 80 = 8
From (1): 50(8) + 30y = 550
⇒ 30y = 550 - 400 = 150
⇒ y = 150 / 30 = 5
Therefore, the price of a chicken is $8 and the price of a duck is $5.
Answer:
6%
Step-by-step explanation:
Simple Interest formula:
S.I=P×R×T/100
where
S.I is simple interest
P is principle amount
R is Annual interest rate
T is time period
[usually represented as (number of months)/12]
so
$18=$400×R/100×9/12
simplify
$18=$3600R/1200
$18=$3R
so R=$18/$3
=6
Therefore,
The Annual Interest Rate is 6%
Hey!
Your point on the graph would be ( -8, 0 ).
We shade the right side of the graph because the inequality shows that x is greater than -8.
*SEE THE GRAPH BELOW*
Hope this helps!
- Lindsey Frazier ♥
Answer:
25x + 5y + z cents
Step-by-step explanation:
1 quarter is worth 25 cents.
1 nickel is worth 5 cents.
1 penny is worth 1 cent.
Therefore, x quarters, y nickels and x pennies will be worth:
(x * 25) + (y * 5) + (z * 1)
= 25x + 5y + z cents
