Home / 386.78-580.43-140.00

Finding the Fourth Proportional to 386.78, 580.43 and 140.00

Calculator

Solution

The fourth proportional to 386.78, 580.43 and 140.00 is: 210.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.78 : 580.43 = 140.00 : x
  2. Step 2: Convert to fraction form
    386.78/580.43 = 140.00/x
  3. Step 3: Cross multiply
    386.78x = 580.43 × 140.00
  4. Step 4: Simplify right side
    386.78x = 81,257.65
  5. Step 5: Solve for x
    x = 81,257.65/386.78
  6. Step 6: Final answer
    x = 210.09

Related Problems

Find fourth proportional to 193.39, 290.22 and 70.00
Half scale
Find fourth proportional to 773.55, 1,160.87 and 279.99
Double scale
Find fourth proportional to 387.78, 581.93 and 141
Similar ratio
Find fourth proportional to 580.16, 870.65 and 209.99
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.