Home / 1,275.50-1,913.20-720.20

Finding the Fourth Proportional to 1,275.50, 1,913.20 and 720.20

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Solution

The fourth proportional to 1,275.50, 1,913.20 and 720.20 is: 1,080.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,275.50 : 1,913.20 = 720.20 : x
  2. Step 2: Convert to fraction form
    1,275.50/1,913.20 = 720.20/x
  3. Step 3: Cross multiply
    1,275.50x = 1,913.20 × 720.20
  4. Step 4: Simplify right side
    1,275.50x = 1,377,886.64
  5. Step 5: Solve for x
    x = 1,377,886.64/1,275.50
  6. Step 6: Final answer
    x = 1,080.27

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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.