Chapter ISG, Problem 3.5STP

To determine

To evaluate the correct statements

Answer to Problem 3.5STP

The correct statement is “The plant was exactly 19.52mm tall 4 days after planting”

Explanation of Solution

Given information:

The function which shows the height of plant is,

  $y=5.23x-1.4$

For statement one, “The plant grows about 36mm per week”

Days (x) = 7

Substituting the values in the function,

  $y=(5.23\times 7)-1.4$

On solving,

  $y=35.21$

Comparing the solution to the statement,

  $36\ne 35.21$

Hence, the statement is incorrect.

For statement two, “The plant was exactly 19.52 mm tall 4 days after planting”

Days (x) = 4

Substituting the values in the function,

  $y=(5.23\times 4)-1.4$

On solving,

  $y=19.52$

Comparing the solution to the statement,

  $19.52=19.52$

Hence, the statement is correct

For statement three, “The plant is about 5cm tall 10days after planting”

Days (x) = 10

Substituting the values in the function,

  $y=(5.23\times 5)-1.4$

On solving,

  $y=24.75$ mm

Converting to the cm,

2.475 cm

Comparing the solution to the statement,

  $19.52=19.52$

Hence, the statement is correct

  $5cm\ne 2.475cm$

Hence, the statement is incorrect

For statement four, “The plant grows 5.23mm every day”

Days (x) = 1

Substituting the values in the function,

  $y=(5.23\times 1)-1.4$

On solving,

  $y=3.83$ mm

Comparing the solution to the statement,

  $5.23\ne 3.83$

Hence, the statement is incorrect