Random or Biased
Population Inferences

Chloe surveys only students who wear a UGA sweatshirt who they think should have made the conference games. Explain.

Biased -- only asked UGA fans


Mrs. Fouche surveyed students about their favorite color. She surveyed 30 random students in 7th grade.
- 8 said red
- 10 said blue
- the remainder said green
If there are 350 students in 7th grade, how many would you expect to say green?

140 students


Mr. Steele created a spinner to determine which football play the offense will play.
- Reverse: 1/3
- Tackle: 0.33
- Dive: 34%
Which football play is least likely to occur?

Tackle is least likely to occur.


6 - (x - 8) = 9

x = 5


Irrational or Rational?


Rational because it is a perfect square


Mr. Harris wants to know if students would rather have hot chocolate or apple cider. He randomly chooses 15 students in 7th and 15 students in 6th grade.

Random -- he asked students from both grades, and found students randomly.

Coach Harrison flipped a coin 60 times. She landed of heads 25 of those times. If she flips the coin 300 times, how many times would you expect her to flip heads? 

125 times


There are 6 red, 10 blue, and 34 yellow marbles in a jar. What is the probability that that you would randomly draw a yellow?
*fraction, decimal, percent, and word

34/50=17/25, 0.68, 68%, likely


3(2x - 8) - 2(x - 10)

3(2x - 8) - 2(x - 10)
6x - 24 - 2x + 20
4x - 4


Sophia is saving money to buy a new computer. She currently has $120 saved, and she plans to save $15 each week. However, she also knows that she will need at least $300 to buy the computer. Let w represent the number of weeks she needs to save to have enough money. Write & solve the inequality.

120 + 15w >= 300

w >= 12

Mrs. Craven wants to know if students would rather watch "The Grinch" or "Polar Express". She asks five students from each of her class by drawing popcicle sticks.

Random -- she asked students from each class by drawing names.


Which of the following is true?
A. Team A has a more varied data set.
B. The teams have no data that overlaps.
C. The median for team B is the same as the maximum of team A. 
D. In both teams, the IQR is 2.

D -- the IQR is 2 for both teams


Roxie is playing Chutes & Ladders. The spinner has 4 equal sections. She will win if she lands at least a 2. What is the probability that will occur?

3/4, 0.75, 75%, likely


Samantha went to the store and bought a pair of shoes for $45. In addition to that, she also bought three t-shirts, each costing x. The total amount she spent was $93. Write the equation & solve.

45 + 3x = 93
$16 per shirt


5x - 8 + x = 2(___x - ____)

What number goes in the blanks to make this statement have NO SOLUTIONS?

3 & 4


The lunchroom wants to know if students would rather eat nachos or quesadilla for lunch Tuesday. She surveys the first 10 students to enter the lunch room.

Biased -- she didn't interview anyone from Soar Street or Eagle Avenue. In addition, she could have asked students who bring their lunch daily.


Myles has the following test scores:
85, 88, 92, and 97
What does he need to earn on the last test to have a 90 in math class?



Lily wants to plan her next vacation. She is taking a map, throwing a dart, and that will determine where she travels next. She states that every country has an equal chance of occurring because they are on the map. Do you agree or disagree? Explain.

Disagree -- each country is a different area, and therefore does not have the same chance of occuring.

4(2x - 7) = 6x + 4

8x - 28 = 6x + 4
2x =32
x = 16


A hiking team starts at 70 feet above sea level. They end up 30 feet below sea level. How far did the travel?

They descended 100 feet.


Landon wanted to know what the most popular game on GimKit was. He interviewed his friends that he knows loves "Don't look down".

Biased -- he asked students who he knows love that version of the game and noone else.


Ms. Crisp wants to know how many movies students have seen this week. She randomly surveyed students at EJMS. How many students would you expect to watch at least 3 movies this week if there are 600 students a EJMS?

9 / 20 = 270 students


The grinch has a 25% chance of choosing a green ornament for his tree. Design a simulation to determine this chance.

A spinner labeled green for 1/4.


56 < 34 - x

x < 22



7^6 times 7^-9