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Finding the Fourth Proportional to 690.64, 953.45 and 428.81

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Solution

The fourth proportional to 690.64, 953.45 and 428.81 is: 591.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.64 : 953.45 = 428.81 : x
  2. Step 2: Convert to fraction form
    690.64/953.45 = 428.81/x
  3. Step 3: Cross multiply
    690.64x = 953.45 × 428.81
  4. Step 4: Simplify right side
    690.64x = 408,848.89
  5. Step 5: Solve for x
    x = 408,848.89/690.64
  6. Step 6: Final answer
    x = 591.99

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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.