MA111 Spring 2010 January 14 1 Handouts Syllabus Worksheet 1 1 and Homework 1 1 2 Reviewed syllabus 3 Worked on question 1 of Worksheet 1 1 in groups reporting out comments with student introductions 1 January 19 1 Handouts Homework 1 2 Worksheet 1 2 2 Reviewed answers to Homework 1 1 including some discussion on sources of data and credibility of websites 3 Demonstrated the website WolframAlpha http www wolframalpha com 4 Collected Homework 1 1 and assigned Homework 1 2 5 Announced quiz for Thursday Bring calculators 6 Began reviewing Introduction to Numbers and Quantities pages 6 7 Discussed how to make conversions by multiplying by one Examples Converting 60 miles per hour to feet per second Converting 1 trillion seconds to years 7 Looked at Worksheet 1 2 items 1 2 and 4 2 January 21 1 Worked on and discussed some problems for Homework 1 2 2 Reviewed some basic facts about percent 5 a 5 means 100 which equals 0 05 25 b 10 is 25 of 40 means 10 0 25 40 or 10 100 40 c Using the second expression above you can set up and solve many typical percent problems 25 x 100 i What is 25 of 40 40 10 25 ii 10 is 25 of what x 100 x 100 iii 10 is what percent of 40 10 40 3 Quiz 1 1 4 Discussed question on percent Last year 50 of the members of the art club were men This year 60 of the members of the art club are men Yet there are fewer men in the art club this year than last year How can this be 3 January 26 1 Passed back Homework 1 1 and Quiz 1 1 2 Collected Homework 1 2 3 Handed out Homework 1 3 4 Reviewed solutions to some of the problems in Homework 1 1 In particular mentioned some issues regarding credibility of websites 5 Reminder Exam 1 is on Thursday February 4 6 Introduction to percent and percent change See pages 22 27 of the text P a P means 100 So divide by 100 to convert a percent to decimal and multiply by 100 to convert a decimal to percent A P b A is P of N means N 100 If you have two pieces of information you can use this to solve for the third P c If you increase A by P to get B this can be expressed as B A 1 100 Using this you can solve for B given A and solve for A given B P d If you decrease A by P to get B this can be expressed as B A 1 100 Using this you can solve for B given A and solve for A given B e If A changes to B and you want to determine the percent change use the formula B A 100 P This works whether B is greater than A in which A case P is positive or B is less than A in which case P is negative f WARNING You cannot reverse an increase of say 20 by decreasing the result by 20 You will NOT return to the original amount 4 January 28 1 Looked at the Street Sign and Himalayan Glaciers websites 2 Worked and extensively discussed Quiz 1 2 5 February 2 1 Exam 1 has been moved to February 9 2 Collection of Homework 1 3 has been moved to February 4 3 Reviewed Homework 1 2 and 1 3 Some points a b c d e f g Correct use of apostrophes in possessives Show your work don t just give the answer Write meaningful sentences e g about ratio and percent What is 1 23 trillion divided by 100 000 Think about types or categories of number misuse not just examples Practice correct rounding There is a difference between percent of and percent more than For example 300 is 150 of 200 but 300 is 50 more than 200 4 Worked on Worksheet 1 3 Percent Change 6 February 4 1 Reminder that Exam 1 will be on Tuesday February 9 2 Worked on the Exam 1 Review handout 3 Solutions to Exam 1 Review handout later posted to course website 7 February 9 1 Exam 1 8 February 11 1 Handout Worksheet 2 1 Answered and discussed the questions 2 Handout Quiz 2 1 Answered and submitted 3 Handout Homework 2 1 4 Case Study 2 2 Read and began to to answer Study Questions 1 3 4 and 5 on page 35 9 February 16 Class canceled due to weather 10 February 18 1 Passed back Exam 1 and indicated that I plan to add 5 points to everyone s raw exam score 2 I will send out an assignment for Homework 2 2 and also post this to the course website later today 3 Exam 2 will be on Tuesday March 2 with topics in percents means and medians and introduction to indices 4 Worked on problems 1 3 4 and 5 on page 35 5 Looked at the government s definition of employed unemployed and not in the labor force 6 Introduced mean median and mode and discussed some circumstances when each is helpful 11 February 23 1 Exam 2 will be on Tuesday March 2 with topics in percents means and medians and introduction to indices 2 Answered questions on Homework 2 1 and collected this assignment 3 Worked on some of the problems of Homework 2 2 4 Introduced the notion of making an index from a table of values 12 February 25 1 Reminder Exam 2 is on Tuesday March 2 2 Answered lingering questions on Homework 2 2 3 Collected Homework 2 2 4 Discussed handout on review questions for Exam 2 5 Began discussing Worksheet 2 2 not on Exam 2 13 March 2 1 Exam 2 14 March 4 1 Discussed the Consumer Price Index The value of a dollar in 2010 is not the same as the value of a dollar in 1980 One gallon of gas cost 1 131 in January 1980 and 2 731 in January 2010 Which was more expensive The CPI allows us to compare the value of a dollar by comparing the cost of purchasing a certain bundle of items In one version the index value was set to 100 in the year 1967 CPI in January 1972 123 2 CPI in January 1980 233 2 CPI in January 2009 632 491 CPI in January 2010 649 098 So 649 098 2010 dollars 233 2 1980 dollars in buying power In 2010 dollars the 1980 gas price becomes 3 148 2010 dollars per 1 gallon of 1980 gas Thus gas was MORE expensive then what was going on in that year The real price has dropped by about 13 percent In 1972 the cost of tuition room and board at Yale for one year was 5000 In 2009 it is 47 500 for the year In 2009 dollars the 1972 cost becomes 25669 So the real price has increased by about 85 percent meaning it is …