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Finding the Fourth Proportional to 774.28, 1,068.50 and 420.20

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Solution

The fourth proportional to 774.28, 1,068.50 and 420.20 is: 579.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    774.28 : 1,068.50 = 420.20 : x
  2. Step 2: Convert to fraction form
    774.28/1,068.50 = 420.20/x
  3. Step 3: Cross multiply
    774.28x = 1,068.50 × 420.20
  4. Step 4: Simplify right side
    774.28x = 448,977.83
  5. Step 5: Solve for x
    x = 448,977.83/774.28
  6. Step 6: Final answer
    x = 579.86

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.