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Finding the Fourth Proportional to 891.54, 1,227.15 and 642.47

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Solution

The fourth proportional to 891.54, 1,227.15 and 642.47 is: 884.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    891.54 : 1,227.15 = 642.47 : x
  2. Step 2: Convert to fraction form
    891.54/1,227.15 = 642.47/x
  3. Step 3: Cross multiply
    891.54x = 1,227.15 × 642.47
  4. Step 4: Simplify right side
    891.54x = 788,400.92
  5. Step 5: Solve for x
    x = 788,400.92/891.54
  6. Step 6: Final answer
    x = 884.31

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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.