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Finding the Fourth Proportional to 720.39, 991.54 and 615.13

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Solution

The fourth proportional to 720.39, 991.54 and 615.13 is: 846.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.39 : 991.54 = 615.13 : x
  2. Step 2: Convert to fraction form
    720.39/991.54 = 615.13/x
  3. Step 3: Cross multiply
    720.39x = 991.54 × 615.13
  4. Step 4: Simplify right side
    720.39x = 609,924.29
  5. Step 5: Solve for x
    x = 609,924.29/720.39
  6. Step 6: Final answer
    x = 846.65

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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.