Genevieve conducted an experiment in which she spun a spinner with four equal-sized sections: green, yellow, red, and blue. The results of her experiment are shown below.
Genevieve's Experiment
Spin Result
1 green
2 green
3 red
4 red
5 green
6 blue
7 yellow
8 green
9 green
10 yellow
Spin Result
11 yellow
12 green
13 red
14 blue
15 green
16 yellow
17 red
18 yellow
19 blue
20 green
Which letter has an experimental probability equal to its theoretical probability?
A.
yellow
B.
green
C.
red
D.
blue
A. A national survey company picks one phone number from each area code in America to call and ask for an opinion on current political issues.
This is an example of random sampling because the national survey company is selecting phone numbers from each area code in America in a random manner, without bias. This allows for a diverse and representative sample of the population to be surveyed.
Yes, I'm sure. Random sampling involves selecting individuals or elements from a population in a way that every member of the population has an equal chance of being selected, without bias. By picking one phone number from each area code in America to conduct the survey, the national survey company is adopting a random sampling method.
In this case, there are 2 possible outcomes for tossing a fair coin (heads or tails) and 2 possible outcomes for rolling a fair number cube less than 3 (1 or 2).
The total number of outcomes when tossing a fair coin followed by rolling a number cube is 2 (coin) * 6 (cube) = 12.
The outcomes where heads followed by a number less than 3 occur are when the coin lands on heads and the cube shows a 1 or 2. There are 2 favorable outcomes for this.
Therefore, the probability of tossing heads followed by rolling a number less than 3 is 2 (favorable outcomes) / 12 (total outcomes) = 1/6.
Therefore, the correct answer is:
B. 1/6
A plane slicing a prism in half parallel to one of its faces will produce a cross-section that is identical in shape to that face. In this case, the smallest face of the prism is the 9-inch by 10-inch face, which is a rectangle.
Therefore, the correct answer is:
D. a 9-inch by 10-inch rectangle
Which of the following is an example of random sampling?
A.
A national survey company picks one phone number from each area code in America to call and ask for an opinion on current political issues.
B.
The school newspaper asks teachers in that middle school how they feel about the behavior of twelve year old boys.
C.
Migrant workers are surveyed on their opinion of mandatory health insurance for companies.
D.
The manager of a restaurant asks customers their opinion on a new salad dressing.
you sure
If Quinn tosses a fair coin and then rolls a fair number cube labeled 1 through 6, what is the probability of tossing heads followed by rolling a number less than 3?
A. 1/3
B. 1/6
C. 6
D. 1/4
you sure
A right rectangular prism has a length of 9 inches, a width of 10 inches, and a height of 11 inches. If a plane slices the prism in half, parallel to its smallest face, which of the following describes the shape of the two-dimensional cross-section?
A.
a 10-inch by 11-inch rectangle
B.
a 9-inch by 11-inch square
C.
a 10-inch by 10-inch square
D.
a 9-inch by 10-inch rectangle
B. green
Genevieve's experiment shows that green appeared 9 times out of 20 spins. Since there are 4 equal-sized sections on the spinner, the theoretical probability of spinning green should be 1/4 or 0.25. In this case, the experimental probability (9/20) is equal to the theoretical probability (0.25) for green.