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Finding the Fourth Proportional to 1,220.90, 1,828.10 and 642.56

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Solution

The fourth proportional to 1,220.90, 1,828.10 and 642.56 is: 962.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,220.90 : 1,828.10 = 642.56 : x
  2. Step 2: Convert to fraction form
    1,220.90/1,828.10 = 642.56/x
  3. Step 3: Cross multiply
    1,220.90x = 1,828.10 × 642.56
  4. Step 4: Simplify right side
    1,220.90x = 1,174,663.94
  5. Step 5: Solve for x
    x = 1,174,663.94/1,220.90
  6. Step 6: Final answer
    x = 962.13

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.