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Finding the Fourth Proportional to 661.78, 913.40 and 440.74

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Solution

The fourth proportional to 661.78, 913.40 and 440.74 is: 608.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.78 : 913.40 = 440.74 : x
  2. Step 2: Convert to fraction form
    661.78/913.40 = 440.74/x
  3. Step 3: Cross multiply
    661.78x = 913.40 × 440.74
  4. Step 4: Simplify right side
    661.78x = 402,571.92
  5. Step 5: Solve for x
    x = 402,571.92/661.78
  6. Step 6: Final answer
    x = 608.32

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Half scale
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Double scale
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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.