Home / 864.78-1,296-395.90

Finding the Fourth Proportional to 864.78, 1,296 and 395.90

Calculator

Solution

The fourth proportional to 864.78, 1,296 and 395.90 is: 593.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    864.78 : 1,296 = 395.90 : x
  2. Step 2: Convert to fraction form
    864.78/1,296 = 395.90/x
  3. Step 3: Cross multiply
    864.78x = 1,296 × 395.90
  4. Step 4: Simplify right side
    864.78x = 513,086.40
  5. Step 5: Solve for x
    x = 513,086.40/864.78
  6. Step 6: Final answer
    x = 593.31

Related Problems

Find fourth proportional to 432.39, 648 and 197.95
Half scale
Find fourth proportional to 1,729.56, 2,592 and 791.80
Double scale
Find fourth proportional to 865.78, 1,297.50 and 396.90
Similar ratio
Find fourth proportional to 1,297.17, 1,944 and 593.85
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.