Name ______Date ______
6.2ACC Practice HW: Random Sampling and making predictions
Determine if the example given represents a random sample or not.
- Mr. Baker is wondering what is the average height of a 7th grader:
1)He selects the first 25 students who come to school
2)He chooses the students in his period 3 class
3)He gives every 7th grade studenta raffle ticket with a number. Then, he selects 25 numbers by drawing them from a container.
4)He chooses 25 students who play soccer after school
5)He assigns a number to every student in the 7th grade. Then he uses the random number generator on his calculator to select 25 students
- You have two concert tickets – 1 for you and 1 for a friend - to your favorite musical artist. You have 6 friends and you can’t decide who to ask.
6)You choose the first person who call you tonight
7)You assign each friend a different number form 1 to 6. You roll a 6-sided die and the number you roll is the friend you take.
8)You tell your friends to meet you after school. You toss a coin to choose between the first two friends who show up.
Use the information given below to make a prediction about a population.
9)In a survey of 300 voters, 68 said they voted for Candidate A. How many votes can Candidate A expect to receive if the population of the town is 10,000?
10)In a capture-recapture study, 97 grizzly bears were tagged and released back into the wild. A month later, 200 bears were captured of which 36 were tagged. About how many grizzly bears are in the population?
11)From a survey of 100 commuters about how they get to work, 38 said they drive their cars, 47 said they take the bus, 14 said they take the subway, and 1 said they ride their bicycle. Out of 4,800 commuters, predict how many will commute to work in each of the following way.
CarBus
SubwayBicycle
12)To determine the consistency of a printer, 100 printed sheets are randomly checked and 4 sheets are defective. About how many defective sheets would be expected if 2,400 sheets were printed?
Some additional kinds of questions
13)You survey 30 students from a population of 150 7th graders. Which statement is not correct?
a)The ratio of those sampled to those not sampled is 30 to 120.
b)One out of every five people in the population was sampled.
c)25% of the students in the population were sampled
d)of the students in the population were sampled
14) A survey was taken asking students to name their favorite summer activity. Two out of every 5 students said going to the beach was their favorite summer activity. If there are 560 students in one school, how many would you expect to say that their favorite summer activity is to go to the beach?
15) A survey found that 85% of people use emoticons on their instant messages. Predict how many of the 2450 students a one middle school use emoticons.