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Finding the Fourth Proportional to 715.17, 986.96 and 420.38

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Solution

The fourth proportional to 715.17, 986.96 and 420.38 is: 580.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.17 : 986.96 = 420.38 : x
  2. Step 2: Convert to fraction form
    715.17/986.96 = 420.38/x
  3. Step 3: Cross multiply
    715.17x = 986.96 × 420.38
  4. Step 4: Simplify right side
    715.17x = 414,896.14
  5. Step 5: Solve for x
    x = 414,896.14/715.17
  6. Step 6: Final answer
    x = 580.14

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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.