Finding the Fourth Proportional to 390.20, 539.49 and 372.99
Calculator
Solution
The fourth proportional to 390.20, 539.49 and 372.99 is: 515.70
Step by Step Solution
- Step 1: Write the proportion equation
390.20 : 539.49 = 372.99 : x - Step 2: Convert to fraction form
390.20/539.49 = 372.99/x - Step 3: Cross multiply
390.20x = 539.49 × 372.99 - Step 4: Simplify right side
390.20x = 201,224.38 - Step 5: Solve for x
x = 201,224.38/390.20 - Step 6: Final answer
x = 515.70
Related Problems
Find fourth proportional to 195.10, 269.75 and 186.50
Half scale
Find fourth proportional to 780.40, 1,078.98 and 745.98
Double scale
Find fourth proportional to 391.20, 540.87 and 373.99
Similar ratio
Find fourth proportional to 585.30, 809.24 and 559.49
1.5x scale
Why These Related Problems?
These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.