Question

The average weight of 7 potted plants is 23 pounds. An 8th potted plant is added to the pallet,

Answer 1

Answer:

The weight of the 8th plant is 39lb

Step-by-step explanation:

Given:

Average Weight of 7 plants = 23lb

Average Weight of 8 plants = 25lb

Required:

Weight of the 8th plant

To solve this, the total weight of the initial 7 plants need to be calculated;

$Average = \frac{Sum-of-weights}{Number-of-Plants}$

Substitute 23 for Average and 7 for Number of plants

$23 = \frac{Sum-of-weights}{7}$

Multiply both sides by 7

$7 * 23 = \frac{Sum-of-weights}{7} * 7$

$161 = Sum-of-weights$

Hence, the 7 plants weigh 161

Represent the weight of the 8th plant with E

When the 8th plant is added;

The sum of the weight becomes 161 + E

And the number of plants becomes 8

The average is calculated as thus

$Average = \frac{Sum-of-weights}{Number-of-Plants}$

$25 = \frac{161 + E}{8}$

Multiply both sides by 8

$8 * 25 = \frac{161 + E}{8} * 8$

$200 = 161 + E$

Subtract 161 from both sides

$200 -161 = 161 - 161 + E$

$39 = E$

Reorder

$E = 39$

Hence, the weight of the 8th plant is 39lb