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Finding the Fourth Proportional to 820.50, 1,130.10 and 645.54

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Solution

The fourth proportional to 820.50, 1,130.10 and 645.54 is: 889.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.50 : 1,130.10 = 645.54 : x
  2. Step 2: Convert to fraction form
    820.50/1,130.10 = 645.54/x
  3. Step 3: Cross multiply
    820.50x = 1,130.10 × 645.54
  4. Step 4: Simplify right side
    820.50x = 729,524.75
  5. Step 5: Solve for x
    x = 729,524.75/820.50
  6. Step 6: Final answer
    x = 889.12

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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.