Home / 517.78-781.54-517.78

Finding the Fourth Proportional to 517.78, 781.54 and 517.78

Calculator

Solution

The fourth proportional to 517.78, 781.54 and 517.78 is: 781.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    517.78 : 781.54 = 517.78 : x
  2. Step 2: Convert to fraction form
    517.78/781.54 = 517.78/x
  3. Step 3: Cross multiply
    517.78x = 781.54 × 517.78
  4. Step 4: Simplify right side
    517.78x = 404,665.78
  5. Step 5: Solve for x
    x = 404,665.78/517.78
  6. Step 6: Final answer
    x = 781.54

Related Problems

Find fourth proportional to 258.89, 390.77 and 258.89
Half scale
Find fourth proportional to 1,035.56, 1,563.08 and 1,035.56
Double scale
Find fourth proportional to 518.78, 783.05 and 518.78
Similar ratio
Find fourth proportional to 776.67, 1,172.31 and 776.67
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.