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Finding the Fourth Proportional to 715.52, 987.40 and 405.08

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Solution

The fourth proportional to 715.52, 987.40 and 405.08 is: 559.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.52 : 987.40 = 405.08 : x
  2. Step 2: Convert to fraction form
    715.52/987.40 = 405.08/x
  3. Step 3: Cross multiply
    715.52x = 987.40 × 405.08
  4. Step 4: Simplify right side
    715.52x = 399,975.99
  5. Step 5: Solve for x
    x = 399,975.99/715.52
  6. Step 6: Final answer
    x = 559.00

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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.