Sampling Methods and Probability

A clothing store manager wants to make sure the paint color on the walls appeals to customers. Which sampling method produces an unbiased, representative sample of the population?

• Survey 35 randomly selected customers at the clothing store each day for 7 days.

• Survey 150 people eating at the food court in the mall.

• Survey every 5th person who enters the food court at the mall.

• Survey every customer at the clothing store on Sunday who is under the age of 30.

Tags

CCSS.7.SP.A.1

CCSS.HSS.IC.A.1

Which statement is true?

• A probability of 1 indicates an event is unlikely to happen.

• A probability of 4/5 indicates an event is likely to happen.

• A probability of 0.25 indicates an event will definitely not happen.

• A probability of –1 indicates an event will definitely happen.

Tags

CCSS.7.SP.C.5

A student collects data to determine the favorite sport among seventh graders at the middle school. Which sampling method produces an unbiased, representative sample of the population?

• Ask 10 randomly selected students from each seventh-grade homeroom.

• Ask every seventh-grade student who rides the bus to school in the morning.

• Ask every student in the middle school who plays a fall sport.

• Ask the first 30 students to arrive to the middle school each morning.

Tags

CCSS.7.SP.A.1

CCSS.HSS.IC.A.1

A costume closet contains 8 dresses, 3 shirts, 5 pairs of pants, and 4 hats. What is the probability of randomly selecting a hat from the costume closet?

• 3/20

• 1/5

• 1/4

• 2/5

Tags

CCSS.7.SP.C.7B

The table shows the favorite flower of a random sample of 75 gardeners from a gardening club. Based on the results from the sample, about how many of the 1,050 gardeners in the gardening club can be expected to say that a tulip is their favorite flower?

• 280 gardeners

• 350 gardeners

• 420 gardeners

• 630 gardeners

Tags

CCSS.7.SP.A.2

A company wants to know the most popular brand of water bought by customers that are 20 to 25 years old in Texas. Which sampling method produces an unbiased, representative sample of the population?

• Randomly survey 250 retired doctors in Texas.

• Survey every 3rd customer in the 20- to 25-year-old age range that buys water at a randomly selected grocery store in Texas.

• Survey the first 250 customers at a randomly selected grocery store in Maine.

• Survey the first 250 people in the 20- to 25-year-old age range the statistician from the company comes across at a fitness event in North Carolina.

Tags

CCSS.7.SP.A.1

CCSS.HSS.IC.A.1

Students in a gym class are randomly assigned to study the rules of baseball, football, or soccer for a class project using a spinner divided into three equal sections, as shown. If the teacher spins the spinner to assign the first student to a sport, what is the probability the student will be assigned to study the rules of football?

• 1/3

• 1/2

• 2/3

• 3/4

Tags

CCSS.7.SP.C.7A

Cards numbered 1 through 25 are placed in a hat. If a student selects 1 card at random, what is the probability the card is 1 digit?

• 0.26

• 0.36

• 0.40

• 0.60

Tags

CCSS.7.SP.C.7B

A box of blocks contains 35 red, 40 blue, and 50 green blocks. If the box only contains red, blue, and green blocks, and a child randomly selects a block, what is the probability the block is red?

• 0.28

• 0.35

• 0.38

• 0.40

Tags

CCSS.7.SP.C.7B

A teacher wants to find out what incentive seventh-grade students prefer. Which group is the most representative of the population of interest?

• all the students in the middle school

• all the seventh-grade students in the robotics club

• every sixth student to walk into the middle school one morning

• six randomly selected students from each seventh-grade class

Tags

CCSS.7.SP.A.1

CCSS.HSS.IC.A.1