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Finding the Fourth Proportional to 715.20, 985.68 and 705.12

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Solution

The fourth proportional to 715.20, 985.68 and 705.12 is: 971.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.20 : 985.68 = 705.12 : x
  2. Step 2: Convert to fraction form
    715.20/985.68 = 705.12/x
  3. Step 3: Cross multiply
    715.20x = 985.68 × 705.12
  4. Step 4: Simplify right side
    715.20x = 695,022.68
  5. Step 5: Solve for x
    x = 695,022.68/715.20
  6. Step 6: Final answer
    x = 971.79

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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.