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time spent online americans spend an average of 4 hours per day online.…

Question

time spent online americans spend an average of 4 hours per day online. if the standard deviation is 26 minutes, find the range in which at least 88.89% of the data will lie. use chebyshevs theorem. round your k to the nearest whole number. at least 88.89% of the data will lie between and minutes.

Explanation:

Step1: Recall Chebyshev's theorem formula

The formula for Chebyshev's theorem is $1-\frac{1}{k^{2}}$, where $1 - \frac{1}{k^{2}}$ is the proportion of data within $k$ standard - deviations of the mean. We are given that $1-\frac{1}{k^{2}}=0.8889$.

Step2: Solve for $k$

$$ LATEXBLOCK0 $$

Step3: Convert the mean to minutes

The mean is 4 hours. Since 1 hour = 60 minutes, the mean $\mu=4\times60 = 240$ minutes. The standard - deviation $\sigma = 26$ minutes.

Step4: Calculate the lower and upper bounds

The lower bound $L=\mu - k\sigma$ and the upper bound $U=\mu + k\sigma$.

$$ LATEXBLOCK1 $$
$$ LATEXBLOCK2 $$

Answer:

162, 318