Fifteen students were selected and asked how many hours each studied for the final exam in statistics. Their answers are recorded here.
$\begin{array}{llllllllllllllll}6 & 4 & 9 & 0 & 0 & 1 & 9 & 0 & 1 & 3 & 7 & 10 & 2 & 9 & 4\end{array}$
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Find the range, variance, and standard deviation. Round the variance to one decimal place and the standard deviation to two decimal places, if necessary.
Part 1 of 3
The range is 10 hours.
Part: $1 / 3$
Part 2 of 3
The variance is

Step 1 ：Given data is \(\begin{array}{llllllllllllllll}6 & 4 & 9 & 0 & 0 & 1 & 9 & 0 & 1 & 3 & 7 & 10 & 2 & 9 & 4\end{array}\)

Step 2 ：The range of the data is the difference between the maximum and minimum values. In this case, the range is \(10 - 0 = 10\) hours.

Step 3 ：To find the variance, we first calculate the mean of the data. The mean is the sum of all the values divided by the number of values.

Step 4 ：The mean of the data is \(\frac{6 + 4 + 9 + 0 + 0 + 1 + 9 + 0 + 1 + 3 + 7 + 10 + 2 + 9 + 4}{15} = 4.333333333333333\)

Step 5 ：We then subtract the mean from each value, square the result, and then find the mean of these squared differences. This gives us the variance.

Step 6 ：The variance of the data is \(12.88888888888889\)

Step 7 ：Final Answer: The variance is \(\boxed{12.9}\) when rounded to one decimal place.