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Finding the Fourth Proportional to 784.49, 1,080.12 and 666.21

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Solution

The fourth proportional to 784.49, 1,080.12 and 666.21 is: 917.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    784.49 : 1,080.12 = 666.21 : x
  2. Step 2: Convert to fraction form
    784.49/1,080.12 = 666.21/x
  3. Step 3: Cross multiply
    784.49x = 1,080.12 × 666.21
  4. Step 4: Simplify right side
    784.49x = 719,593.29
  5. Step 5: Solve for x
    x = 719,593.29/784.49
  6. Step 6: Final answer
    x = 917.28

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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.