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Finding the Fourth Proportional to 820.40, 1,130.82 and 713.79

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Solution

The fourth proportional to 820.40, 1,130.82 and 713.79 is: 983.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.40 : 1,130.82 = 713.79 : x
  2. Step 2: Convert to fraction form
    820.40/1,130.82 = 713.79/x
  3. Step 3: Cross multiply
    820.40x = 1,130.82 × 713.79
  4. Step 4: Simplify right side
    820.40x = 807,162.35
  5. Step 5: Solve for x
    x = 807,162.35/820.40
  6. Step 6: Final answer
    x = 983.86

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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.