What is the percent increase from $3 to $4?

To find the percent increase from $3 to $4, you first need to determine the actual increase in the amount, which is calculated by subtracting the original value from the new value. In this case, the increase is $4 - $3 = $1.

Next, to calculate the percent increase, you divide the increase by the original amount and then multiply by 100 to convert it to a percentage. So, the calculation would be:

[

\text{Percent Increase} = \left(\frac{\text{Increase}}{\text{Original Amount}}\right) \times 100

]

[

= \left(\frac{1}{3}\right) \times 100 \approx 33.3%

]

This means the increase from $3 to $4 corresponds to a 33.3% increase. The step of dividing the increase ($1) by the original amount ($3) is crucial, as it accurately reflects the change in relation to the starting value. Hence, the correct choice is accurately represented by the answer that states a percent increase of 33.3%.