Question

the means and mean absolute deviations of the amount of rain that fell each day in a local city, last week and this week, are shown in the table. the difference in the mean rainfall is approximately what percent of the mean absolute deviation of the this weeks rainfall? 23% 67% 8% 27%

Explanation:

Step1: Calculate the difference in means

The mean of last week is \(19.7\) cm and the mean of this week is \(19.3\) cm. The difference in means is \(|19.7 - 19.3|=0.4\) cm.

Step2: Set up the percentage formula

We want to find what percent \(0.4\) is of \(5.2\) (the mean absolute deviation of this week). The formula for percentage is \(\frac{\text{Part}}{\text{Whole}}\times100\%\). Here, the part is \(0.4\) and the whole is \(5.2\). So the calculation is \(\frac{0.4}{5.2}\times 100\%\).

Step3: Perform the division and multiplication

\(\frac{0.4}{5.2}\approx0.0769\). Then \(0.0769\times100\% = 7.69\%\approx8\%\)

Answer:

\(8\%\)