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Finding the Fourth Proportional to 715.64, 987.19 and 518.81

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Solution

The fourth proportional to 715.64, 987.19 and 518.81 is: 715.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.64 : 987.19 = 518.81 : x
  2. Step 2: Convert to fraction form
    715.64/987.19 = 518.81/x
  3. Step 3: Cross multiply
    715.64x = 987.19 × 518.81
  4. Step 4: Simplify right side
    715.64x = 512,157.81
  5. Step 5: Solve for x
    x = 512,157.81/715.64
  6. Step 6: Final answer
    x = 715.67

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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.