Find the standard deviation for the group of data items. \( 99,10,11,12,13 \) The standard deviation is (Round to two decimal places as needed.)

To calculate the standard deviation, we first need to find the mean (average) of the data set. 1. **Calculate the Mean:** \[ \text{Mean} = \frac{99 + 10 + 11 + 12 + 13}{5} = \frac{145}{5} = 29 \] 2. **Calculate the Deviations from the Mean:** \[ 99 - 29 = 70, \quad 10 - 29 = -19, \quad 11 - 29 = -18, \quad 12 - 29 = -17, \quad 13 - 29 = -16 \] 3. **Square the Deviations:** \[ 70^2 = 4900, \quad (-19)^2 = 361, \quad (-18)^2 = 324, \quad (-17)^2 = 289, \quad (-16)^2 = 256 \] 4. **Sum of Squared Deviations:** \[ 4900 + 361 + 324 + 289 + 256 = 5840 \] 5. **Variance (for population):** \[ \text{Variance} = \frac{5840}{5} = 1168 \] 6. **Standard Deviation:** \[ \text{Standard Deviation} = \sqrt{1168} \approx 34.19 \] So, the standard deviation for the group of data items \( 99, 10, 11, 12, 13 \) rounded to two decimal places is **34.19**.