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Finding the Fourth Proportional to 672.79, 928.80 and 420.79

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Solution

The fourth proportional to 672.79, 928.80 and 420.79 is: 580.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    672.79 : 928.80 = 420.79 : x
  2. Step 2: Convert to fraction form
    672.79/928.80 = 420.79/x
  3. Step 3: Cross multiply
    672.79x = 928.80 × 420.79
  4. Step 4: Simplify right side
    672.79x = 390,823.00
  5. Step 5: Solve for x
    x = 390,823.00/672.79
  6. Step 6: Final answer
    x = 580.90

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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.