Home / 370.40-555.71-139.31

Finding the Fourth Proportional to 370.40, 555.71 and 139.31

Calculator

Solution

The fourth proportional to 370.40, 555.71 and 139.31 is: 209.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    370.40 : 555.71 = 139.31 : x
  2. Step 2: Convert to fraction form
    370.40/555.71 = 139.31/x
  3. Step 3: Cross multiply
    370.40x = 555.71 × 139.31
  4. Step 4: Simplify right side
    370.40x = 77,412.49
  5. Step 5: Solve for x
    x = 77,412.49/370.40
  6. Step 6: Final answer
    x = 209.00

Related Problems

Find fourth proportional to 185.20, 277.85 and 69.65
Half scale
Find fourth proportional to 740.79, 1,111.41 and 278.61
Double scale
Find fourth proportional to 371.40, 557.21 and 140.31
Similar ratio
Find fourth proportional to 555.59, 833.56 and 208.96
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.