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Finding the Fourth Proportional to 818.80, 1,128.75 and 621.97

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Solution

The fourth proportional to 818.80, 1,128.75 and 621.97 is: 857.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.80 : 1,128.75 = 621.97 : x
  2. Step 2: Convert to fraction form
    818.80/1,128.75 = 621.97/x
  3. Step 3: Cross multiply
    818.80x = 1,128.75 × 621.97
  4. Step 4: Simplify right side
    818.80x = 702,048.64
  5. Step 5: Solve for x
    x = 702,048.64/818.80
  6. Step 6: Final answer
    x = 857.41

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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.