average | MathCelebrity Forum

# average

1. ### If 2x + y = 7 and y + 2z = 23, what is the average of x, y, and z?

If 2x + y = 7 and y + 2z = 23, what is the average of x, y, and z? A. 5 B. 7.5 C. 15 D. 12.25 Add both equations to get all variables together: 2x + y + y + 2z = 23 + 7 2x + 2y + 2z = 30 We can divide both sides by 2 to simplify: (2x + 2y + 2z)/2= 30/2 x + y + z = 15 Notice: the average of...

3. ### What is the average of 7 consecutive numbers if the smallest number is called n?

What is the average of 7 consecutive numbers if the smallest number is called n? First number = n Second number = n + 1 Third number = n + 2 Fourth number = n + 3 Fifth number = n + 4 Sixth number = n + 5 Seventh number = n + 6 Average = Sum of all numbers / Total numbers Average = (n + n...
4. ### two numbers have an average of 2100 and one number is \$425 more than the other number. What are the

two numbers have an average of 2100 and one number is \$425 more than the other number. What are the numbers Let the first number be x and the second number be y. We're given two equations: (x + y)/2 = 2100 (Average) y = x + 425 Rearrange equation (1) by cross multiplying x + y = 2 * 2100 x +...
5. ### A football team loses 27 yards total during its first 3 plays. On average, what is the yards per pl

A football team loses 27 yards total during its first 3 plays. On average, what is the yards per play for these 3 plays? A loss of yards means negative yardage. Average Yards per play = Total Yards / Total plays Average Yards per play = -27/3 Average Yards per play = -9 or 9 yard loss
6. ### The average age of 15 men is 25 years. What is their total age in years?

The average age of 15 men is 25 years. What is their total age in years? Average Age = Total Ages/Total Men 25 = Total Ages / 15 Cross multiply and we get: Total Ages = 15 * 25 Total Ages = 375
7. ### the average of eighty-five and a number m is ninety

the average of eighty-five and a number m is ninety Average of 2 numbers means we add both numbers and divide by 2: (85 + m)/2 = 90 Cross multiply: m + 85 = 90 * 2 m + 85 = 180 To solve this equation for m, we type it in our math engine and we get: m = 95
8. ### A set of 19 scores has a mean of 6.3. A new score of 8 is then included in the data set. What is th

A set of 19 scores has a mean of 6.3. A new score of 8 is then included in the data set. What is the new mean? We know the mean formula is: Sum of scores / Number of Scores = Mean We're given mean = 6.3 and number of scores = 19, so we have: Sum of scores / 19 = 6.3 Cross multiply: Sum of...
9. ### The mean age of 10 women in an office is 30 years old. The mean age of 10 men in an office is 29 yea

The mean age of 10 women in an office is 30 years old. The mean age of 10 men in an office is 29 years old. What is the mean age (nearest year) of all the people in the office? Mean is another word for average. Mean age of women = Sum of all ages women / number of women We're told mean age of...
10. ### 12 laps in 18 minutes . What is the average time per lap?

12 laps in 18 minutes . What is the average time per lap? 18/12 = 1.5 minutes per lap
11. ### 6 boys have a mean age of 10 years and 14 girls have a mean age of 5 work out the mean age of the 20

6 boys have a mean age of 10 years and 14 girls have a mean age of 5 work out the mean age of the 20 children Calculate Sum of boys ages: Sum of boys ages/6 = 10 Cross multiply, and we get: Sum of boys ages = 6 * 10 Sum of boys ages = 60 Calculate Sum of girls ages: Sum of girls ages/14 = 5...
12. ### A road construction team built a 114 mile road over a period of 19 months what was their average bui

A road construction team built a 114 mile road over a period of 19 months what was their average building distance per a month Average building distance = miles built / months of building Average building distance = 114/19 Average building distance = 6 miles per month
13. ### a baseball player has 9 hits in his first 60 at bats. how many consecutive hits would he need to bri

a baseball player has 9 hits in his first 60 at bats. how many consecutive hits would he need to bring his average up to 0.400? Let the amount of consecutive hits needed be h. We have: hits / at bats = Batting Average Plugging in our numbers, we get: (9 + h)/60 = 0.400 Cross multiply: 9 + h =...
14. ### A chicken farm produces ideally 700,000 eggs per day. But this total can vary by as many as 60,000 e

A chicken farm produces ideally 700,000 eggs per day. But this total can vary by as many as 60,000 eggs. What is the maximum and minimum expected production at the farm? Calculate the maximum expected production: Maximum expected production = Average + variance Maximum expected production =...
15. ### 5000 union members of a financially troubled company accepted a 17% pay cut. The company announced t

5000 union members of a financially troubled company accepted a 17% pay cut. The company announced that this would save them approximately \$108 million annually. Based on this information, calculate the average annual pay of a single union member Let the full salary of the union members be s...
16. ### At 2:18 Pm, a parachutist is 4900 feet above the ground. At 2:32 pm, the parachutist is 2100 above t

At 2:18 Pm, a parachutist is 4900 feet above the ground. At 2:32 pm, the parachutist is 2100 above the ground. Find the average rate of change in feet per minute Average Rate of Change = Change in Distance / Change in time Average Rate of Change = (4900 - 2100) / (2:32 - 2:18) Average Rate of...
17. ### The arithmetic mean (average) of 17, 26, 42, and 59 is equal to the arithmetic mean of 19 and N. Wha

The arithmetic mean (average) of 17, 26, 42, and 59 is equal to the arithmetic mean of 19 and N. What is the value of N ? Average of the first number set is using our average calculator is: 36 Now, the mean (average) or 19 and N is found by adding them together an dividing by 2: (19 + N)/2...
18. ### A luncheon for 14 guests cost \$468.00. What was the average cost per guest?

A luncheon for 14 guests cost \$468.00. What was the average cost per guest? Average Cost per Guest = Total Cost / Number of Guests Average Cost per Guest = \$468 / 14 Average Cost per Guest = \$33.43
19. ### Narda has \$250 and Ding has \$170. How much money must Narda give to Ding so that each of them will h

Narda has \$250 and Ding has \$170. How much money must Narda give to Ding so that each of them will have an equal amount of money? Find the difference of Narda and Ding's money: Difference = Narda - Ding Difference = 250 - 170 Difference = 80 Find half the difference: Half the difference = 80/2...
20. ### A restaurant earns \$1073 on Friday and \$1108 on Saturday. Write and solve an equation to find the am

A restaurant earns \$1073 on Friday and \$1108 on Saturday. Write and solve an equation to find the amount x (in dollars) the restaurant needs to earn on Sunday to average \$1000 per day over the three-day period. Let Sunday's earnings be s. With 3 days, we divide our sum of earnings for 3 days by...