MS 150 Statistics q11 11.2 • Name:

LibraryCirc 1997Circ 2006
Aguilar 1340650
Akron 32262966
Baca 2253900
Bent 6589
Costilla 9882500
Cotopaxi 75778200
Dacono 24544829
Dolores 79247235
East Cheyenne9991688
Flagler 33801240
Fleming 72025704
Fowler 49952860
Gilpin 56977570
Haxtun 19523752
Hinsdale 9236
Holly 24971219
Huerfano 5812
Hugo 24131231
Jackson 28323037
John 4523
Julesburg 19231569
Kiowa 57265100
La Veta69563073
Las Animas4230
Lincoln 4547
Lyons 59094834
Mancos 45083039
Manitou 32737056
Manzanola 305153
Meeker 48447690

Over the past ten years children have had increasing access to electronic game playing devices such as Nintendo, xBox, and Sony Playstation. If children are increasingly staying at home, what of the older self-entertainment options such as reading books and the public library? More broadly, are children checking out fewer books to read? The data in the table are children's books circulation numbers for thirty smaller public libraries in Colorado. One set of data is for 1997, the other set is for nine years later in 2006.

Does the mean children's books circulation data suggest that fewer books are being checked out by children in 2006 than did so in 1997?

Run a t-test for a difference of the means for the data shown. Write up your conclusions below. Use both statistical language and common everyday English to tell me about whether circulation rates for children's books have changed and, if so, in what direction from 1997 to 2006.

Note that you cannot run a paired t-test: not all libraries have data for both years. Use a t-test for independent samples.

The data is annual children's book circulation for the two years cited. Sources:
http://www.lrs.org/public/stats_1997.php
http://www.lrs.org/public/cannedstats.php?year=2006

For reference purposes, here is the original data, all libraries. Do not use this on the quiz!

LibraryCirc 1997Circ 2006
Adams 245392275051
Aguilar 1340650
Akron 32262966
Alamosa 2804630502
Arapahoe 8697611763709
Aurora 390040494287
Baca 2253900
Basalt 2433824409
Bent 6589
Berthoud 2054623138
Boulder 405324312517
Broomfield 134876250755
Burlington 2000022000
Canon City6000064614
Clear Creek105679718
Conejos 901824922
Cortez 22144
Costilla 9882500
Cotopaxi 75778200
Craig-Moffat 38057
Dacono 24544829
Delta 6525775344
Denver 19194421750300
Dolores 79247235
Dolores 1160013061
Douglas 5235182611026
Durango 7977178270
Eagle Valley68038124920
East Cheyenne9991688
East Morgan2026424302
East Routt6822073264
Elbert 2431544456
Englewood 7488857158
Estes 5342457764
Flagler 33801240
Fleming 72025704
Florence 12808
Fort 591825850941
Fort Morgan3952836401
Fowler 49952860
Garfield 77459159392
Gilpin 56977570
Grand 5210686960
Gunnison 2734528653
Haxtun 19523752
Hinsdale 9236
Holly 24971219
Holyoke 1139717081
Huerfano 5812
Hugo 24131231
Ignacio 242212960
Jackson 28323037
Jefferson 15007431638220
John 4523
Julesburg 19231569
Kiowa 57265100
La Junta3289737736
La Veta69563073
Lafayette 67519149591
Lake 2282912253
Lamar 3785931255
Las Animas4230
Limon 553613284
Lincoln 4547
Littleton 110646173318
Longmont 276637326408
Louisville 155973192534
Loveland 220775349601
Lower 11496
Lyons 59094834
Mancos 45083039
Manitou 32737056
Manzanola 305153
Meeker 48447690
Mesa 262505235780
Mineral 50009750
Moffat 21058
Montrose 38714113056
N. 1147915774
Northeast 8589689881
Nucla 32242230
Ordway 820037971
Ouray 39335023
Ovid 265
Park 3719729556
Penrose 83559174
Pikes 14692892395216
Pine 50047100
Pitkin 4458052114
Pueblo 286690346236
Rampart 2865553265
Rangely 95339130
Red 25353255
Ridgeway 7835
Rio 2568328809
Rocky 913410414
Saguache 3132715
San Miguel 11521343760
San Miguel 238944466
Security 8112363123
Silverton 915517000
South Chaffee2268730954
South Routt54323423
Southern 675014680
Spanish Peaks4946
Sterling 3975947304
Stratton 32031848
Summit 3285843447
Swink 67528401
Trinidad 2113220608
Upper San Juan2192214554
Vail 37009000
Weld 256950738479
Wellington 806015771
West 100004858
West 77767640
Westminster 159475644372
Wetmore 4310
Windsor 4905177148
Wray 12000
Yuma 122305720