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Finding the Fourth Proportional to 770.50, 1,062.28 and 645.63

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Solution

The fourth proportional to 770.50, 1,062.28 and 645.63 is: 890.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    770.50 : 1,062.28 = 645.63 : x
  2. Step 2: Convert to fraction form
    770.50/1,062.28 = 645.63/x
  3. Step 3: Cross multiply
    770.50x = 1,062.28 × 645.63
  4. Step 4: Simplify right side
    770.50x = 685,831.30
  5. Step 5: Solve for x
    x = 685,831.30/770.50
  6. Step 6: Final answer
    x = 890.11

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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.