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Finding the Fourth Proportional to 918.72, 1,378.08 and 457.08

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Solution

The fourth proportional to 918.72, 1,378.08 and 457.08 is: 685.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    918.72 : 1,378.08 = 457.08 : x
  2. Step 2: Convert to fraction form
    918.72/1,378.08 = 457.08/x
  3. Step 3: Cross multiply
    918.72x = 1,378.08 × 457.08
  4. Step 4: Simplify right side
    918.72x = 629,887.64
  5. Step 5: Solve for x
    x = 629,887.64/918.72
  6. Step 6: Final answer
    x = 685.61

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Half scale
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Double scale
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Similar ratio
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.