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Finding the Fourth Proportional to 642.79, 888.06 and 421.66

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Solution

The fourth proportional to 642.79, 888.06 and 421.66 is: 582.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.79 : 888.06 = 421.66 : x
  2. Step 2: Convert to fraction form
    642.79/888.06 = 421.66/x
  3. Step 3: Cross multiply
    642.79x = 888.06 × 421.66
  4. Step 4: Simplify right side
    642.79x = 374,459.38
  5. Step 5: Solve for x
    x = 374,459.38/642.79
  6. Step 6: Final answer
    x = 582.55

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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.