1. **Problem Statement:** Calculate the mean, median, mode, range, variance, and standard deviation for the time (in minutes) it takes smokers to fall asleep given the data: 69.3, 56.0, 22.1, 47.6, 53.2, 48.1, 52.7, 60.2, 43.8, 34.4.
2. **Mean Formula:** The mean is the sum of all data points divided by the number of points.
$$\text{Mean} = \frac{\sum x_i}{n}$$
3. **Calculate Mean:**
$$\sum x_i = 69.3 + 56.0 + 22.1 + 47.6 + 53.2 + 48.1 + 52.7 + 60.2 + 43.8 + 34.4 = 487.4$$
$$n = 10$$
$$\text{Mean} = \frac{487.4}{10} = 48.74$$
4. **Median Formula:** The median is the middle value when data is ordered. For even $n$, median is average of two middle values.
5. **Calculate Median:**
Order data: 22.1, 34.4, 43.8, 47.6, 48.1, 52.7, 53.2, 56.0, 60.2, 69.3
Middle values (5th and 6th): 48.1 and 52.7
$$\text{Median} = \frac{48.1 + 52.7}{2} = 50.4$$
6. **Mode:** No repeated values, so no mode.
7. **Range Formula:**
$$\text{Range} = \text{max} - \text{min}$$
8. **Calculate Range:**
$$\text{Range} = 69.3 - 22.1 = 47.2$$
9. **Variance Formula:**
$$s^2 = \frac{\sum (x_i - \bar{x})^2}{n-1}$$
10. **Calculate Variance:**
Calculate each squared deviation:
$(69.3 - 48.74)^2 = 420.67$
$(56.0 - 48.74)^2 = 52.67$
$(22.1 - 48.74)^2 = 705.38$
$(47.6 - 48.74)^2 = 1.30$
$(53.2 - 48.74)^2 = 20.83$
$(48.1 - 48.74)^2 = 0.41$
$(52.7 - 48.74)^2 = 15.68$
$(60.2 - 48.74)^2 = 131.14$
$(43.8 - 48.74)^2 = 24.40$
$(34.4 - 48.74)^2 = 205.15$
Sum of squared deviations:
$$\sum (x_i - \bar{x})^2 = 1577.63$$
$$s^2 = \frac{1577.63}{9} = 175.29$$
11. **Standard Deviation:**
$$s = \sqrt{175.29} = 13.24$$
**Final answers:**
- Mean = 48.74
- Median = 50.4
- Mode = None
- Range = 47.2
- Variance = 175.29
- Standard Deviation = 13.24
Smoking Sleep Stats D7636A
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