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Finding the Fourth Proportional to 715.77, 986.78 and 479.75

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Solution

The fourth proportional to 715.77, 986.78 and 479.75 is: 661.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.77 : 986.78 = 479.75 : x
  2. Step 2: Convert to fraction form
    715.77/986.78 = 479.75/x
  3. Step 3: Cross multiply
    715.77x = 986.78 × 479.75
  4. Step 4: Simplify right side
    715.77x = 473,407.71
  5. Step 5: Solve for x
    x = 473,407.71/715.77
  6. Step 6: Final answer
    x = 661.40

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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.