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Finding the Fourth Proportional to 889.95, 1,227.36 and 642.90

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Solution

The fourth proportional to 889.95, 1,227.36 and 642.90 is: 886.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    889.95 : 1,227.36 = 642.90 : x
  2. Step 2: Convert to fraction form
    889.95/1,227.36 = 642.90/x
  3. Step 3: Cross multiply
    889.95x = 1,227.36 × 642.90
  4. Step 4: Simplify right side
    889.95x = 789,069.74
  5. Step 5: Solve for x
    x = 789,069.74/889.95
  6. Step 6: Final answer
    x = 886.65

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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.