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Finding the Fourth Proportional to 1,127.20, 1,555.30 and 661.20

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Solution

The fourth proportional to 1,127.20, 1,555.30 and 661.20 is: 912.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,127.20 : 1,555.30 = 661.20 : x
  2. Step 2: Convert to fraction form
    1,127.20/1,555.30 = 661.20/x
  3. Step 3: Cross multiply
    1,127.20x = 1,555.30 × 661.20
  4. Step 4: Simplify right side
    1,127.20x = 1,028,364.36
  5. Step 5: Solve for x
    x = 1,028,364.36/1,127.20
  6. Step 6: Final answer
    x = 912.32

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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.