# Errata for Math in Society

## Errata and Changes for Math in Society

Errors in Edition 2.5

Probability

• Solution to Try it Now 3 is incorrect: P(at least one is white) = 1 - P(neither is white) = 1 - P(not white socks AND not white tee) = 1 - 4/10*4/7 = 1 - 16/70 = 54/70 = 27/35 ~~ 77.1%
• Solution to Try it Now 9 is incorrect: the numerator should be 10*4=40

Changes Made Edition 2.4 -> 2.5

Corrected these typos/errors:

Weighted Voting

• Try it Now 2: The answer for the quota of 16 is wrong. The answer is correct for a quota of 15.  For a quota of 16, all three players have veto power.
• Try it Now 4: Between the list of coalitions and the table, the sentence should read: P1 is pivotal 3 times, P2 is pivotal 3 time, and P3 is pivotal 0 times.

Finance

• Example 14: The remaining balance after 5 years should be $162,758, resulting in$34,292.80 to interest.
• Exercise 15: The answer for part a should be \$320,243.29.

Probability

• Example 17, the final calculation should be 1/102 + 1/102 = 2/102 = 1/51

Sets

• Exercise 12 should be C subset U , not C subset D

Historical Counting

• Exercise 1: The answer is incorrect; the 3 jars in the middle should be x3, making the total count 36.
• Exercise 33, 35: The problem was represented in dots using base 10 rather than base 20.

Cryptography

• Exercise 1: The list of letters above the question didn't include W
• Exercise 9: The answer should be MNI YNE TBA AEH RTA TEA TAI LRE A

Problem solving

• In Unit conversions, added a note that fluid ounces are a capacity measurement, and should not be used as a weight measurement.
• Info for meatloaf problem: Clarified that 15ounces is a net weight.

Apportionment

• In Alabama Paradox, corrected "Maine" to "Rhode Island"
• In New States Paradox, corrected by swapping "New York" and "Maine"

Graph Theory

• In Example #1, added labels to the vertices
• Clarified definition of vertex
• #22: Clarified distances were in kilometers

Scheduling

• #27: Fixed lettering

Finance

• #1: Inserted "one-time" with the interest rate
• #4: Inserted "annual" with the interest rate

Statistics

• Clarified the definition of simple random sample to say "every member of the population and any group of members has an equal probability"

Sets

• #43: Should say "and" instead of "or"

Solutions:

• Growth Models #7c: The answer was missing a 7; should be 794,061
• Probability #7: The answer should be 1/5! = 1/(5P5) = 1/120.