Probability and Statistics — Answer Key
Part A: Fix the Sentence
Each sentence has an error. Rewrite it correctly on the line.
1. Fix the sentence:
The spinner have four equal sector.
Corrected: The spinner has four equal sectors.
Spinner is singular so the verb is has, and sectors is plural to match four.
2. Fix the sentence:
There is 26 red cards in the deck.
Corrected: There are 26 red cards in the deck.
Cards is plural, so the matching verb must be are, not is, in this sentence.
3. Fix the sentence:
One out of six are a small chance.
Corrected: One out of six is a small chance.
The phrase one out of six names one chance, so it pairs with the singular verb is.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. A spinner has 4 equal colored sectors. The probability of landing on red is 1/4.
Equal sectors make each color equally likely, so P(red) = 1/4.
2. From a 52-card deck, the probability of drawing a red card is 1/2.
26 red cards out of 52 simplify to 1/2, the chance of drawing red.
3. The probability of rolling a 6 on a fair number cube can be read as 1 out of 6.
We say 1 out of 6 to express one favorable outcome among six equal possibilities.
4. Written as a percent, the probability 1/2 equals 50%.
The fraction 1/2 equals 50/100, which is 50%, a common probability conversion.
Part C: Short Answer
Answer each question in one or two complete sentences.
1. A spinner has 4 equal sectors: red, blue, green, yellow. What is P(blue) as a fraction and a percent?
Sample answer: P(blue) = 1/4 = 25% because one of four equal sectors is blue.
Equal sectors give P = favorable/total, and 1/4 = 25/100 = 25%.
2. Out of 52 cards, what is the probability of drawing an ace? Show as a fraction.
Sample answer: There are 4 aces in 52 cards, so P(ace) = 4/52 = 1/13.
Probability is favorable over total; 4/52 reduces to 1/13.