Answer
Find out the possible heights of her fourth plant.
To prove
Let us assume that the possible heights of her fourth plant be x.
As given
Millie needs the average height of the plants she is buying to be atleast 73 inches.
She has selected three plants that are 70, 71, and 72 inches tall.
Average formula
[tex]Average formula = \frac{Total\ heights \ of\ plants}{Total\ number\ of\ plants}[/tex]
Put the value
Here Total numbers of flowers = 4
Put in the formula
[tex]73\leq \frac{x + 70 + 71 +72}{4}[/tex]
[tex]73\times 4 \leq (x + 70 + 71 +72)[/tex]
[tex]292 \leq x + 213[/tex]
[tex]292 - 213 \leq x[/tex]
79 ≤ x
Therefore the possible height of the fourth plant be 79 .
