## Elementary Statistics: A Step-by-Step Approach with Formula Card 9th Edition

Chebyshev’s theorem The proportion of values from a data set that will fall within k standard deviations of the mean will be at least $1−1/k^2$, where k is a number greater than 1 (k is not necessarily an integer). 35. Time Spent Online Americans spend an average of 3 hours per day online. If the standard deviation is 32 minutes, find the range in which at least 88.89% of the data will lie. Let $1-1/k^2=0.8889$ we have $k=3$ and $3s=3\times32=96$minutes or 1hr36minutes. The range will then be 1hr24minutes to 4hr36minutes