Home / 612.48-918-428.88

Finding the Fourth Proportional to 612.48, 918 and 428.88

Calculator

Solution

The fourth proportional to 612.48, 918 and 428.88 is: 642.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    612.48 : 918 = 428.88 : x
  2. Step 2: Convert to fraction form
    612.48/918 = 428.88/x
  3. Step 3: Cross multiply
    612.48x = 918 × 428.88
  4. Step 4: Simplify right side
    612.48x = 393,711.84
  5. Step 5: Solve for x
    x = 393,711.84/612.48
  6. Step 6: Final answer
    x = 642.82

Related Problems

Find fourth proportional to 306.24, 459 and 214.44
Half scale
Find fourth proportional to 1,224.96, 1,836 and 857.76
Double scale
Find fourth proportional to 613.48, 919.50 and 429.88
Similar ratio
Find fourth proportional to 918.72, 1,377 and 643.32
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.