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Finding the Fourth Proportional to 756.90, 1,042.66 and 646.74

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Solution

The fourth proportional to 756.90, 1,042.66 and 646.74 is: 890.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    756.90 : 1,042.66 = 646.74 : x
  2. Step 2: Convert to fraction form
    756.90/1,042.66 = 646.74/x
  3. Step 3: Cross multiply
    756.90x = 1,042.66 × 646.74
  4. Step 4: Simplify right side
    756.90x = 674,329.93
  5. Step 5: Solve for x
    x = 674,329.93/756.90
  6. Step 6: Final answer
    x = 890.91

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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.