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Finding the Fourth Proportional to 500.42, 690.63 and 287.81

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Solution

The fourth proportional to 500.42, 690.63 and 287.81 is: 397.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    500.42 : 690.63 = 287.81 : x
  2. Step 2: Convert to fraction form
    500.42/690.63 = 287.81/x
  3. Step 3: Cross multiply
    500.42x = 690.63 × 287.81
  4. Step 4: Simplify right side
    500.42x = 198,770.22
  5. Step 5: Solve for x
    x = 198,770.22/500.42
  6. Step 6: Final answer
    x = 397.21

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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.