Home / 522.40-720.86-289.50

Finding the Fourth Proportional to 522.40, 720.86 and 289.50

Calculator

Solution

The fourth proportional to 522.40, 720.86 and 289.50 is: 399.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    522.40 : 720.86 = 289.50 : x
  2. Step 2: Convert to fraction form
    522.40/720.86 = 289.50/x
  3. Step 3: Cross multiply
    522.40x = 720.86 × 289.50
  4. Step 4: Simplify right side
    522.40x = 208,688.97
  5. Step 5: Solve for x
    x = 208,688.97/522.40
  6. Step 6: Final answer
    x = 399.48

Related Problems

Find fourth proportional to 261.20, 360.43 and 144.75
Half scale
Find fourth proportional to 1,044.80, 1,441.72 and 579
Double scale
Find fourth proportional to 523.40, 722.24 and 290.50
Similar ratio
Find fourth proportional to 783.60, 1,081.29 and 434.25
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.