The mean weight of the packages Joan shipped was 2.5 pounds. If Joan mailed four packages and three of them had weights of 1.8, 3.2 and 2.7 pounds, then what did the other package weigh?

2.3 pounds

Step-by-step explanation:

First, the mean is equal to the sum divided by the number of numbers.

There are four packages, so there are four numbers. Let's say the fourth package has a weight of x. We can then write

mean = sum / number of numbers

2.5 = (1.8+3.2+2.7+x)/4

multiply both sides by 4 to remove the denominator

10 = 1.8+3.2+2.7+x

10 = 7.7 + x

subtract 7.7 from both sides to isolate the x

x = 2.3 pounds

d (5 x (-20)) * (100 x (0.7))

step-by-step explanation:

5÷1/100 * -.7 *-20

copy dot flip

5*100 * -.7 *-20

rearrange

5*-20   * 100 *-.7

-100   *-70

7000

step-by-step explanation:

if you want to solve percent error follow these steps.

1. subtract the accepted value from the experimental value.

2. take the absolute value of step 1.

3. divide that answer by the accepted value.

4. multiply that answer by 100 and add the % symbol to express the answer as a percentage.

if you want to solve percent of change just do this.

1. work out the difference (increase) between the two numbers you are comparing.

2. divide the increase by the original number and multiply the answer by 100. if your answer is a negative number then this is a percentage decrease.

hope this : )