Mean = {10 + 20 + 30}{3}
Mean = {60}{3} = 20
Net Income = Gross Income − Taxes
“If your gross income is $3,000 and you pay $500 in taxes, what is your net income?”
$2,500
y = 2x + 3
What is y when x = 4?
y = 2(4) + 3 = 8 + 3 = 11
Range = max(5, 12, 7, 20, 3) - min (5, 12, 7, 20, 3)
Range = 20 - 3 = 17
Savings = Income − Expenses
“You earn $2,000 a month and spend $1,600. What is your savings for the month?”
$400
P = 100 x 1.05^t
What is P when t = 2?
P = 100 x 1.05^2 = 100 x 1.1025 = 110.25
Median of (8, 2, 5)
2, 5, 8 => Median = 5
Simple Interest = Principal × Rate × Time
“You invest $1,000 at 5% simple interest for 2 years. What is the interest earned?”
$100
($1,000 × 0.05 × 2)
y = x^2 - 4x + 3
What is y when x = 3?
y = 3^2 - 4(3) + 3 = 9 - 12 + 3 = 0
Mode of (4, 4, 6, 6, 6, 8, 8)
Mode = 6
Interest = Balance × (APR ÷ 12)
“Your credit card balance is $1,200 with a 24% APR. What is the interest charge for one month?”
$24
($1,200 × 0.02)
P = {1000}{1 + 9e^-0.5t
What is P when t = 0?
P = {1000}{1 + 9e^0 = {1000}{1 + 9} = {1000}{10} = 100
Standard deviation of (4, 4, 4)
Mean = 4, Variance = 0, SD = 0}
A = P(1 + r)^t
“You deposit $500 at 6% interest compounded annually for 1 year. What is the total amount at the end of the year?”
$530
($500 × 1.06)
Q = 5 L^0.5 K^0.5
What is Q when L = 16 and K = 9?
Q = 5 x 16^0.5 x 9^0.5 = 5 x 4 x 3 = 5 x 12 = 60