Do various occupational groups differ in their diets? A Britishstudy of this question compared 95 drivers and 57 conductors ofLondon double-decker buses. The conductors' jobs require morephysical activity. The article reporting the study gives the dataas \"Mean daily consumption ± (se).\" Some of the study resultsappear below. Drivers Conductors
Total calories 2828 ± 44 2842 ± 49
Alcohol (grams) 0.27 ± 0.06 0.44 ± 0.05
What justifies the use of the pooled two-sample t test?
The similarity of the sample means suggests that the populationstandard deviations are likely to be different.
The similarity of the sample standard deviations suggests thatthe population standard deviations are likely to be different.
The similarity of the sample means suggests that the populationstandard deviations are likely to be similar.
The similarity of the sample standard deviations suggests thatthe population standard deviations are likely to be similar.
Is there significant evidence at the 5% level that conductorsconsume more calories per day than do drivers? Use the pooledtwo-sample t test to obtain the P-value. (Give answers to 3 decimalplaces.)
t =
df =
P-value =
