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Finding the Fourth Proportional to 820.64, 1,133.28 and 690.68

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Solution

The fourth proportional to 820.64, 1,133.28 and 690.68 is: 953.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.64 : 1,133.28 = 690.68 : x
  2. Step 2: Convert to fraction form
    820.64/1,133.28 = 690.68/x
  3. Step 3: Cross multiply
    820.64x = 1,133.28 × 690.68
  4. Step 4: Simplify right side
    820.64x = 782,733.83
  5. Step 5: Solve for x
    x = 782,733.83/820.64
  6. Step 6: Final answer
    x = 953.81

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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.