In an experiment, five rooms were carpeted and five were left uncarpeted. The rooms are similar in size and function. After a suitable period of time, the concentration of bacteria in the air was measured (in units of bacteria per cubic metre) in all of these rooms. The data and summaries are provided:
The researcher wants to investigate whether carpet makes a difference (either increases or decreases) in the mean bacterial concentration in air and decides to conduct a two-sample t statistic to compare the two sample means. Based on the analysis above, which of the following is a reasonable conclusion?

Question

In an experiment, five rooms were carpeted and five were left uncarpeted. The rooms are similar in size and function. After a suitable period of time, the concentration of bacteria in the air was measured (in units of bacteria per cubic metre) in all of these rooms. The data and summaries are provided:  
 The researcher wants to investigate whether carpet makes a difference (either increases or decreases) in the mean bacterial concentration in air and decides to conduct a two-sample t statistic to compare the two sample means. Based on the analysis above, which of the following is a reasonable conclusion?

Answer

There is very little evidence (P < 0.05) that the mean bacterial concentration in carpeted rooms is greater than that in uncarpeted rooms.

Answer

There is very little evidence (P > 0.40) that the mean bacterial concentration in carpeted rooms is greater than that in uncarpeted rooms.

Answer

There is evidence (P < 0.05) that the mean bacterial concentration in carpeted rooms is greater than that in uncarpeted rooms.

Answer

There is evidence (P > 0.40) that the mean bacterial concentration in carpeted rooms is greater than that in uncarpeted rooms.

	mean	standard deviation
Carpeted rooms:	184	27.0
Uncarpeted rooms:	172	17.9

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In an experiment, five rooms were carpeted and five were left uncarpeted. The r...

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