Final answer:
The mean of a set of numbers is the average, the median is the middle value when sorted, and the mode is the most frequently occurring number. To find these, one must perform calculations on the given data set. Additionally, the S&P 500 is mentioned as another method of measuring stock market performance.
Step-by-step explanation:
To calculate the mean, median, and mode of the given closing stock prices, we need to follow certain statistical methods. The mean is the average of all the numbers, obtained by adding all the values together and then dividing by the count of the values. The median is the middle value when all the values are arranged in ascending order – if there is an even number of values, it is the average of the two middle values. The mode is the value that appears most frequently in the data set.
Another measure of stock market performance is the Standard & Poor's 500 (S&P 500), which averages the changes in prices of stocks that are traded to determine overall market performance, including markets like the NYSE, AMEX, and OTC.