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:
Each color have a equal chance.
Corrected: Each color has an equal chance.
Each is singular, so we use has; equal starts with a vowel sound, so an, not a.
2. Fix the sentence:
Hearts is one of four suit in the deck.
Corrected: Hearts is one of four suits in the deck.
Four describes more than one suit, so the noun must be plural: suits.
3. Fix the sentence:
The chance of red are fifty percent.
Corrected: The chance of red is fifty percent.
Chance is singular, so the verb is is, even with the prepositional phrase of red.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. On a 4-color spinner with red, blue, green, yellow, P(green) = 1/4.
Equal sectors mean each color has probability 1/4.
2. There are 13 hearts in a deck of 52. P(heart) = 1/4.
13/52 = 1/4 since hearts are one of four equal suits.
3. The probability of flipping heads on a fair coin can be written as 1 out of 2.
Two equal outcomes give 1 out of 2 for heads, a basic probability.
4. As a percent, P(heart) = 1/4 equals 25%.
1/4 = 25/100 = 25%, a quick conversion students should memorize.
Part C: Short Answer
Answer each question in one or two complete sentences.
1. Explain in words and as a fraction the probability of drawing the ace of spades from a full deck.
Sample answer: There is 1 ace of spades in 52 cards, so P = 1 out of 52, or 1/52.
Only one card matches, so favorable = 1 and total = 52.
2. A spinner shows 4 equal colors. Write P(yellow) as a fraction and a percent.
Sample answer: P(yellow) = 1/4 = 25% because one of four equal sectors is yellow.
Equal sectors give 1/4; 1/4 equals 25/100 or 25%.