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choli [55]
2 years ago
9

During a test period, an experimental group of 10 vehicles using an 85 percent ethanol-gasoline mixture showed mean CO2 emission

s of 240 pounds per 100 miles, with a standard deviation of 20 pounds. A control group of 14 vehicles using regular gasoline showed mean CO2 emissions of 252 pounds per 100 miles with a standard deviation of 15 pounds. A quick comparison of the sample variances suggests that the population variances are:
a. probably equal.
b. probably unequal.
c. incomparable.
Mathematics
1 answer:
Aleksandr-060686 [28]2 years ago
8 0

Answer:

Probably unequal  ( B )

Step-by-step explanation:

<u>experimental group = 10</u>

using 85% ethanol gasoline

mean = 240 pounds per 100 miles

standard deviation = 20 pounds

<u>control group = 14 vehicles </u>

using regular gasoline

mean = 252 pounds per 100 miles

standard deviation = 15 pounds

comparing  the sample variance of each group shows that they are probably unequal using the equation below

Variance for a sample set of data = ∑ ( x - X ) ^2 / n - 1

where n = number of events

X = mean value

x = value of events

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