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Finding the Fourth Proportional to 720.90, 992.66 and 615.20

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Solution

The fourth proportional to 720.90, 992.66 and 615.20 is: 847.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.90 : 992.66 = 615.20 : x
  2. Step 2: Convert to fraction form
    720.90/992.66 = 615.20/x
  3. Step 3: Cross multiply
    720.90x = 992.66 × 615.20
  4. Step 4: Simplify right side
    720.90x = 610,676.39
  5. Step 5: Solve for x
    x = 610,676.39/720.90
  6. Step 6: Final answer
    x = 847.10

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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.