#12 What is another way to describe an event with a probability of 0?
impossible
#32 What is the probability of rolling a number less than 2 on a number cube?
1/6 . . . there's 1 number less than 2 on a dice . . . . and 6 total numbers on the dice
#25 what is the measure of a straight angle?
180 degrees
#28. What is Q1? See graph in study guide
40. Q1 is the bottom/lower side of the box
#24 Which is not a name for the angle shown? (see picture and options in study guide)
D. angle C . . . named by all 3 points which form it or by the vertex(corner)
#16 Emily is a very good student. She is more likely to attend class than to miss class. Which could be the probability that she misses class tomorrow? (see study guide for options)
B. 0.1 . . . Probability has to be between 0 and 1 so A and D are automatically out. She doesn't miss often so needs lower probability.
#19 number cube is weighted so number don't have same probability. See model in study guide. What is P(number greater than 3)?
7/12 . . . add probabilities for rolling a 4, 5, or 6 together. 2/12 + 2/12 + 3/12 = 7/12
#18 Suppose a plane passes through the center of a square pyramid perpendicular to the base. Which 2D figure is formed? (see options in study guide)
D. A triangle
#31 according to the survey described, what was the population of the survey? "A recent online survey of 5000 teenagers from across the US shows 2 out of 3 teenagers participate in after school activities."
population is all teenagers.
#23 For which survey is the data collected a census? (see choices in study guide)
A. a survey of all the students in your math class shows 2 out of 5 of those students like hip hop best
Why? all students were surveyed
#15 The computer club at HMS has 6th, 7th, and 8th grade members. See probability model in study guide. What is P(not 7th grader)? SIMPLIFY YOUR ANSWER
13/20 . . . 6th and 8th grade is NOT 7th grade. P(6th or 8th) = 9/40 + 17/40 = 26/40 simplified to 13/20
A. tossing 5 coins
Explanation: probability a single kitten is female is 50% . . . matches a coin probability. toss 5 coins, one for each kitten in the litter
#13 If the diameter of a circle is 18 feet, which is closest to the circumference?
A. 56.52 feet . . . C = pi*diameter = 18*pi = 56.55
#22 According to the survey described here, what was the sample of the survey? "A recent telephone survey of 900 teenagers aged 16 - 19 from across the state shows 1 out of 4 of them drive themselves to school."
Most general correct answer = "900 teens surveyed" or Most specific correct answer = "900 teens aged 16 - 19 from across the state"
#30. Julia wants to calculate the mean age of the 200 people attending the saturday matinee at the movie theater. She selects 4 attendees at random and calculates their mean age. What can you conclude? see choices in study guide
A. sample size is too small to give reliable conclusion
#17 Which experiment has a non-uniform probability model? (see choices in study guide)
D. Tossing pair of # cubes and finding sum
#26. William has a 3 pt shooting average of 80%. He wants to determine the number of points he can expect to score if he takes 5 shots. Which describes one trial of a simulation for this situation? (see options in study guide)
B. Generate 5 random integers from 1 to 10 and see how many times the numbers 1 to 8 are generated.
Explanation: 5 random integers for the 5 shots he'd take. Numbers 1-8 because there is an 80% chance of getting one of those from the numbers 1-10.
D. A square pyramid . . . because it gets smaller as you go up the pyramid
B. The population is the 50 framed drawings
#35 Rico spins the spinner twice and determines the product of the spins. What is P(product = 20)? see diagram in study guide
2/9 . . . list out all possible combination of spins and the product of each 2*2 = 4, 2*4 = 8, 2*5=10, 4*2 = 8, 4*4=16, 4*5=20, 5*2=10, 5*4=20, 5*5=25. Two of those have a product of 20, out of 9 possible combinations.
#11 Jenna rolled a number cube twice and determined the sum. Which outcomes are equally likely? (see study guide for options)
C. a sum of 4 and a sum of 10
#14. Benjamin is selecting embellishments for child's dresser . . . see study guide for rest of question. SIMPLIFY YOUR ANSWER!!
3/40 . . . P(cloud) = 3/9 or 1/3, P(dog) = 3/5, P(cloud) = 3/8. Compound probability so multiply 1/3 * 3/5 * 3/8 to get 9/120 which simplifies to 3/40.
#48 What is the surface area of the square pyramid? see picture in study guide
20250 yd2 . . . find area of the square base (75 * 75 = 5625) and area of the 4 triangle faces (4 * 0.5 * 75 * 97.5 = 14625) . . . the 90 yds is totally irrelevant. add the square area and triangle areas together. 5625 + 14625 = 20250
#21 Find the MAD of the data: 112, 134, 150, 98, 120, 68, 116. Round to nearest whole number
18 . . . calculate mean first (114). Find how far each data point is from the mean (2, 20, 36, 16, 6, 46, 2). Find the mean of the distances (18)
#33 Carey has a bag of marbles . . . see rest of question and chart in study guide. What is the difference between the theoretical and experimental probability of picking a green marble?
1/50 . . . Theoretical P(green) = 1/10 because 1 green marble in bag out of 10 total marbles. Experimental P(green) = 4/50 because the chart says so. Difference means subtract so 1/10 = 5/50 and subtract 5/50 - 4/50 to get 1/50