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Finding the Fourth Proportional to 661.53, 912.50 and 428.64

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Solution

The fourth proportional to 661.53, 912.50 and 428.64 is: 591.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.53 : 912.50 = 428.64 : x
  2. Step 2: Convert to fraction form
    661.53/912.50 = 428.64/x
  3. Step 3: Cross multiply
    661.53x = 912.50 × 428.64
  4. Step 4: Simplify right side
    661.53x = 391,131.86
  5. Step 5: Solve for x
    x = 391,131.86/661.53
  6. Step 6: Final answer
    x = 591.25

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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.