Use the accompanying radiation levels $\left(\right.$ in $\left.\frac{\mathrm{W}}{\mathrm{kg}}\right)$ for 50 different cell phones. Find the percentile $P_{70}$. \[ \begin{array}{llllllllll} 0.26 & 0.27 & 0.30 & 0.49 & 0.58 & 0.65 & 0.65 & 0.70 & 0.78 & 0.84 \\ 0.88 & 0.89 & 0.91 & 0.94 & 0.95 & 0.98 & 1.02 & 1.04 & 1.06 & 1.08 \\ 1.11 & 1.12 & 1.13 & 1.14 & 1.14 & 1.15 & 1.15 & 1.16 & 1.18 & 1.20 \\ 1.22 & 1.24 & 1.25 & 1.25 & 1.28 & 1.28 & 1.31 & 1.31 & 1.31 & 1.33 \\ 1.33 & 1.37 & 1.39 & 1.42 & 1.44 & 1.44 & 1.46 & 1.47 & 1.52 & 1.54 \end{array} \] $P_{70}=\square \frac{W}{\mathrm{~kg}}$ (Type an integer or decimal rounded to two decimal places as needed.)

Step 1 ：The percentile of a set of data is the value below which a certain percent of the data fall. So, the 70th percentile, denoted \(P_{70}\), is the value below which 70% of the data fall.

Step 2 ：To find this, we first need to sort the data in ascending order, which it already is.

Step 3 ：Then, we need to find the index of the 70th percentile. This can be calculated using the formula \(i = \frac{P}{100}(N + 1)\), where \(P\) is the percentile (in this case 70), and \(N\) is the number of data points (in this case 50).

Step 4 ：We then round this index to the nearest whole number. If the index is not a whole number, we will need to interpolate between the two nearest values.

Step 5 ：Using the formula, we find that \(i = 35.7\).

Step 6 ：Since this is not a whole number, we interpolate between the 35th and 36th values in our data set, which are 1.28 and 1.28 respectively.

Step 7 ：Final Answer: \(P_{70}=\boxed{1.28} \frac{W}{\mathrm{~kg}}\)