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Finding the Fourth Proportional to 777.69, 1,072.71 and 515.70

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Solution

The fourth proportional to 777.69, 1,072.71 and 515.70 is: 711.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    777.69 : 1,072.71 = 515.70 : x
  2. Step 2: Convert to fraction form
    777.69/1,072.71 = 515.70/x
  3. Step 3: Cross multiply
    777.69x = 1,072.71 × 515.70
  4. Step 4: Simplify right side
    777.69x = 553,196.55
  5. Step 5: Solve for x
    x = 553,196.55/777.69
  6. Step 6: Final answer
    x = 711.33

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1.5x scale

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.