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Finding the Fourth Proportional to 691.34, 953.78 and 428.90

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Solution

The fourth proportional to 691.34, 953.78 and 428.90 is: 591.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    691.34 : 953.78 = 428.90 : x
  2. Step 2: Convert to fraction form
    691.34/953.78 = 428.90/x
  3. Step 3: Cross multiply
    691.34x = 953.78 × 428.90
  4. Step 4: Simplify right side
    691.34x = 409,069.33
  5. Step 5: Solve for x
    x = 409,069.33/691.34
  6. Step 6: Final answer
    x = 591.71

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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.