Presentation is loading. Please wait.

Presentation is loading. Please wait.

Advanced Math Topics 8.2 Selecting a Random Sample.

Similar presentations


Presentation on theme: "Advanced Math Topics 8.2 Selecting a Random Sample."— Presentation transcript:

1 Advanced Math Topics 8.2 Selecting a Random Sample

2 Obtaining a random sample is very important in obtaining accurate information about a population. In 1936, the Literary Digest sent out ten million surveys to a list of its subscribers and to people in the telephone listing. After reviewing their two million returned ballots, they concluded that Alfred E. Landon would win the election. Franklin Roosevelt carried 46 of the 48 states and won the election by a landslide. The sample that the newspaper took was not a random sample. Why? Some ways to obtain a complete random sample include using a random number generator on a computer or calculator, placing numbers in a hat and selecting them, or using a table of random numbers(Table VI in the appendix).

3 A college of 30,000 students wants to interview 8 randomly selected students to ask them about the new university logo. Each student has been assigned a number from 00001 to 30,000. Using column 1 in your table, randomly select 8 student numbers. Col./Line(1) 110480 222368 324130 442167 537570 677921 799562 896301 989579 1085475 1128918 1263553 1309429 1410365 1507119 1651085 1702368 1801011 1952162 2007056 Student #’s 10480, 22368, 24130, 28918, 09429, 28918, 09429, 10365, 07119, 02368. 30,000 pick 8

4 A hotel wants to randomly select 10 of its 750 guests for a customer satisfaction survey. Using column 4, randomly select 10 hotel guest numbers. (4) 02011 85393 97265 61680 16656 42751 69994 07972 10281 53988 33276 03427 92737 85689 08178 51259 60268 94904 58586 09998 14346 Guest #’s 020, 616, 166, 427, 699, 079, 102, 539 332, 034. 750 pick 10

5 From the HW P. 405 4) Each welfare recipient in Lawrence has a case number from 1 to 3000. Government officials are going to audit 20 recipients randomly. Using columns 13 and 14, select the case numbers. The case numbers are 0126, 1063, 0558, 1859, 2997, 2855, 0594, 2562, 1829, 0784, 1277, 2056, 0010, 0654, 2372, 1637, 1295, 2285, 1851, and 2528.

6 HW P. 405 #2, 4, 7-10


Download ppt "Advanced Math Topics 8.2 Selecting a Random Sample."

Similar presentations


Ads by Google