For a new study conducted by a fitness magazine,
240
females were randomly selected. For each, the mean daily calorieconsumption was calculated for a September-February period. Asecond sample of
210
females was chosen independently of the first. For each of them,the mean daily calorie consumption was calculated for aMarch-August period. During the September-February period,participants consumed a mean of
2385.5
calories daily with a standard deviation of
222
. During the March-August period, participants consumed a meanof
2414.5
calories daily with a standard deviation of
252.5
. The population standard deviations of daily calories consumedfor females in the two periods can be estimated using the samplestandard deviations, as the samples that were used to compute themwere quite large. Construct a
90%
confidence interval for
−μ1μ2
, the difference between the mean daily calorie consumption
μ1
of females in September-February and the mean daily calorieconsumption
μ2
of females in March-August. Then complete the table below
| What isthe lower limit of the 90% confidence interval? | |
| What isthe upper limit of the 90% confidence interval? | |
