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Finding the Fourth Proportional to 1,080.36, 1,490.40 and 638.28

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Solution

The fourth proportional to 1,080.36, 1,490.40 and 638.28 is: 880.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,080.36 : 1,490.40 = 638.28 : x
  2. Step 2: Convert to fraction form
    1,080.36/1,490.40 = 638.28/x
  3. Step 3: Cross multiply
    1,080.36x = 1,490.40 × 638.28
  4. Step 4: Simplify right side
    1,080.36x = 951,292.51
  5. Step 5: Solve for x
    x = 951,292.51/1,080.36
  6. Step 6: Final answer
    x = 880.53

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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.