7.10 The ages (in days) at time of death for samples of 11 girls and 16 boys
who died of sudden infant death syndrome are given in Table E7.10. Do
these indicate a gender di¤erence? Name your test and state clearly your
null and alternative hypotheses and choice of test size.
TABLE E7.10
Females Males
53 46 115
56 52 133
60 58 134
60 59 175
78 77 175
87 78
102 80
117 81
134 84
160 103
277 1147.11 An experimental study was conducted with 136 five-year-old children
in four Quebec schools to investigate the impact of simulation games
designed to teach children to obey certain tra‰c safety rules. The trans-
fer of learning was measured by observing children’s reactions to a
quasi-real-life model of tra‰c risks. The scores on the transfer of learn-
ing for the control and attitude/behavior simulation game groups are
summarized in Table E7.11. Test to investigate the impact of simula-
tion games. Name your test and state clearly your null and alternative
hypotheses and choice of test size.
TABLE E7.11
Summarized
Data ControlSimulation
Game
n 30 33
x 7.9 10.1
s 3.7 2.37.12 In a trial to compare a stannous fluoride dentifrice (A) with a commer-
cially available fluoride-free dentifrice (D), 270 children received A and
250 received D for a period of three years. The numberxof DMFS
increments (i.e., the number of new decayed, missing, and filled tooth
surfaces) was obtained for each child. Results were:
EXERCISES 275