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Finding the Fourth Proportional to 921.61, 1,271.81 and 528.69

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Solution

The fourth proportional to 921.61, 1,271.81 and 528.69 is: 729.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    921.61 : 1,271.81 = 528.69 : x
  2. Step 2: Convert to fraction form
    921.61/1,271.81 = 528.69/x
  3. Step 3: Cross multiply
    921.61x = 1,271.81 × 528.69
  4. Step 4: Simplify right side
    921.61x = 672,390.59
  5. Step 5: Solve for x
    x = 672,390.59/921.61
  6. Step 6: Final answer
    x = 729.59

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Double scale
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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.