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Finding the Fourth Proportional to 715.53, 987.40 and 405.03

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Solution

The fourth proportional to 715.53, 987.40 and 405.03 is: 558.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.53 : 987.40 = 405.03 : x
  2. Step 2: Convert to fraction form
    715.53/987.40 = 405.03/x
  3. Step 3: Cross multiply
    715.53x = 987.40 × 405.03
  4. Step 4: Simplify right side
    715.53x = 399,926.62
  5. Step 5: Solve for x
    x = 399,926.62/715.53
  6. Step 6: Final answer
    x = 558.92

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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.