Finding Arithmetic Mean

In a given translation project, three translators each took sections of a book to translate. The first translator took 15000 words, which he translated at a rate of 500 words per 20 minutes. The second translator took 200000 words, which he translated at a rate of 1250 words per half hour. The third took 10000 words, which he translated at a rate of 250 words per 15 minutes. In terms of words per hour, what was the overall average translation rate for this project?

A group of ten candy bars has an average cost of $0.89 per candy bar. How many bars must be bought at the cost of $0.72 a piece to bring the average down to $0.80?

Consider the given set of numbers 70, 81, 91, 83, 88, and 55. A new number equal to a 12% increase in the median of this set is added to the list. What percentage larger is the mean of the new list in comparison with the original?

Find the arithmetic mean of the following series of numbers: 1, 2, 2, 3, 4, 5, 11, 12

On a given exam, four students have an average score of 81 points.  If another student takes the exam, what must he or she score in order to increase the overall average to at least 83 points?

Bill runs for 30 minutes at 8 mph and then runs for 15 minutes at 13mph. What was his average speed during his entire run?

Sample Set A has 25 data points with an arithmetic mean of 50. Sample Set B has 75 data points with an arithmetic mean of 100. Quantity A: The arithmetic mean of the 100 data points encompassing A and B Quantity B: 80

The average (arithmetic mean) of x, y and z is 15. If w is 10, then what is the average of w, x, y and z?

The combined height of John and Sandy is 130 inches.  Sandy, John, and Allen together have a combined height of 215 inches.  Sandy and Allen have combined height of 137 inches.  How tall is John?

Column A                                                  
The mean of the sample of numbers 2, 5, and 10.                           
Column B 
The mean of the sample of numbers 1, 5, and 15.