To solve the given problem, we need to perform the following steps:
(a) Calculate the mean price of the tires.
(b) Calculate the median price of the tires.
(c) Calculate the standard deviation of the tire prices.
The mean price of the tires is calculated by summing all the prices and dividing by the number of prices. Given the prices:
\[ \{88, 116, 98, 78, 82, 92, 94, 89, 94, 81, 108, 113, 100, 96, 86, 92, 74, 99, 91\} \]
The mean price is:
\[ \text{Mean} = \frac{\sum \text{prices}}{19} = 93.21 \]
The median price is the middle value when the prices are arranged in ascending order. For 19 prices, the median is the 10th value in the sorted list. The sorted prices are:
\[ \{74, 78, 81, 82, 86, 88, 89, 91, 92, 92, 94, 94, 96, 98, 99, 100, 108, 113, 116\} \]
The median price is:
\[ \text{Median} = 92.0 \]
The standard deviation measures the amount of variation or dispersion of the prices. It is calculated using the formula:
\[ \sigma = \sqrt{\frac{\sum (x_i - \mu)^2}{N}} \]
Where \( \mu \) is the mean price and \( N \) is the number of prices. The standard deviation is:
\[ \sigma = 10.81 \]
- The mean price of the tires is \( \boxed{93.21} \).
- The median price of the tires is \( \boxed{92.0} \).
- The standard deviation of the tire prices is \( \boxed{10.81} \).