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Finding the Fourth Proportional to 1,127, 1,555.32 and 661.40

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Solution

The fourth proportional to 1,127, 1,555.32 and 661.40 is: 912.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,127 : 1,555.32 = 661.40 : x
  2. Step 2: Convert to fraction form
    1,127/1,555.32 = 661.40/x
  3. Step 3: Cross multiply
    1,127x = 1,555.32 × 661.40
  4. Step 4: Simplify right side
    1,127x = 1,028,688.65
  5. Step 5: Solve for x
    x = 1,028,688.65/1,127
  6. Step 6: Final answer
    x = 912.77

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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.