Solve x2 = 81
x = +9 and -9
*All square roots have a positive and negative solution.
What is the percent change (increase/decrease) formula?
difference in amounts = % x original amount
When do you flip the inequality symbol when solving an inequality?
When multiplying or dividing both sides of the inequality by a negative number.
All of the probabilities of events of a situation should add up to ______.
1 or 100%
What are the two formulas you can use to find the circumference of a circle?
C = pi x diameter
C = 2 x pi x radius
Write and solve an equation to find the side length of a cube shaped box if its volume is 125 cubic inches.
Will 10 one-inch cubes fit along one edge of the cube? Explain why or why not.
V = s3
125 = s3
5 inches = s
No b/c 10 > 5.
Does the equation 3y + 1 = -6x + 1 show a proportional relationship?
Yes b/c when you isolate y, you get y = -2x which follows the format y = kx where k = -2
Ava's chicken lays 10 eggs per hour. She gives 2 eggs to each of her 3 neihgbors. Write an expression to show how many eggs Ava gives away per hour.
10h - 6
When selecting a sample of a population, should it be both representative and random or just one of the two? Explain.
BOTH
A sample should be representative so that it is fully reflecting all types of people in the population, not targeting a specific group.
A sample should also be random so that there is no bias.
3 Part Question (must get all 3 correct):
What is the relationship between <1 and <8?
What is the relationship between <4 and <7?
Point out another angle relationship.
<1 and <8 are alt. ext. angles
<4 and <7 are same side int. angles
Sample Answer: <2 and <7 are alt. int. angles
List the following numbers in order from least to greatest:
√5, 3.8, 1/2, -4, -10/4
-4, -10/4, 1/2, √5, 3.8
Ms. Lewis made 90% of her shots from the free throw line. She made 18 shots.
Ms. Bal made 70% of her shots from the free throw line. She made 21 shots.
How many more shots did Ms. Bal attempt than Ms. Lewis? Use the percent equation to solve.
Ms. Lewis attempted 20 and Ms. Bal attempted 30, 10 more shots.
Write an equation for the following scenario. Define your variable:
Monroe Township has a population of 48,600 people. The population has increased by 10% in the past year.
Let x = the original population
x + 0.1x = 48,600 or 1.1x = 48,600
Of the 510 students in the sixth grade, 90 of them are in accelerated math. If there are 4,080 students in the district, how many would you expect to be in accelerated math?
720 students
Do these side lengths sqrt(21), sqrt(99), 11 form a right triangle? Why or why not?
No b/c 21 + 99 should equal 11^2 which is 121
a^2 + b^2 does not equal c^2
Approximate the value of √220 to the nearest tenth by using perfect squares.
14.8
James guessed that he would score a 1200 on the SAT (Scholastic Aptitude Test). He was surprised to see he actually scored a 1310. What was the percent error of James’s SAT score?
Round the percent to the nearest tenth.
110/1310 = 8.4% error
Connor is mailing some letters at the post office. He only has $10 to spend. Stamps cost 50¢ each. He also needs to mail a package that costs $7.65. How many letters can Connor mail at the post office? Round your final answer to a whole number. Note: Each letter needs one stamp to be mailed.
He can mail at most 4 letters.
What is the 5-number summary of the following data set?
3, 6, 8, 2, 12, 9, 1, 1, 8
Min: 1
Q1: 1.5
Q2 (median): 6
Q3: 8.5
Max: 12
Find the exact distance between the points (2,0) and (0,2) on the coordinate plane.
sqrt(8)
Do not round...then it is not the "exact" distance.
Convert 3.6212121... to a mixed number (3.621, where only 2 and 1 repeat)
x = 3585/990 = 3 and 615/990
Stefan sells Jin a bicycle for $114 and a helmet for $18. The total cost for Jin is 120% of what Stefan spent originally to buy the bike and helmet. How much did Stefan spend originally?
How much money did he make by selling the bicycle and helmet to Jin?
He spent $110 originally and made $22.
The difference of two numbers is 32. The greater number is 10 less than 8 times the smaller number. Find the two numbers.
x = 38 and y = 6
Find the Mean Absolute Deviation of the data set:
3, 6, 8, 2, 12, 9, 1, 1, 12
Leave your answer as a fraction.
Mean: 6
Differences: 3, 0, 2, 4, 6, 3, 5, 5, 6
Average of Differences: 34/9
MAD: 34/9 or 3 7/9
A baseball is stored in a 14 inch cube shaped box for safekeeping. The baseball has a diameter of 8 inches. How much empty space is in the box?
*Round the sphere volume to the nearest whole #
Use: V = s^3 and V = (4/3)(pi)(r)^3
V(cube) = 2744 cubic inches
V(sphere) = 267.94666... or about 268 cubic inches
V(cube) - V(sphere) = About 2476 cubic inches of empty space