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Finding the Fourth Proportional to 912.96, 1,256.64 and 688.32

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Solution

The fourth proportional to 912.96, 1,256.64 and 688.32 is: 947.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    912.96 : 1,256.64 = 688.32 : x
  2. Step 2: Convert to fraction form
    912.96/1,256.64 = 688.32/x
  3. Step 3: Cross multiply
    912.96x = 1,256.64 × 688.32
  4. Step 4: Simplify right side
    912.96x = 864,970.44
  5. Step 5: Solve for x
    x = 864,970.44/912.96
  6. Step 6: Final answer
    x = 947.44

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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.