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Finding the Fourth Proportional to 690.63, 953.38 and 428.79

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Solution

The fourth proportional to 690.63, 953.38 and 428.79 is: 591.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.63 : 953.38 = 428.79 : x
  2. Step 2: Convert to fraction form
    690.63/953.38 = 428.79/x
  3. Step 3: Cross multiply
    690.63x = 953.38 × 428.79
  4. Step 4: Simplify right side
    690.63x = 408,799.81
  5. Step 5: Solve for x
    x = 408,799.81/690.63
  6. Step 6: Final answer
    x = 591.92

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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.