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Finding the Fourth Proportional to 665.38, 918.43 and 455.48

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Solution

The fourth proportional to 665.38, 918.43 and 455.48 is: 628.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.38 : 918.43 = 455.48 : x
  2. Step 2: Convert to fraction form
    665.38/918.43 = 455.48/x
  3. Step 3: Cross multiply
    665.38x = 918.43 × 455.48
  4. Step 4: Simplify right side
    665.38x = 418,319.63
  5. Step 5: Solve for x
    x = 418,319.63/665.38
  6. Step 6: Final answer
    x = 628.70

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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.