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Finding the Fourth Proportional to 990.10, 1,485.12 and 470.47

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Solution

The fourth proportional to 990.10, 1,485.12 and 470.47 is: 705.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    990.10 : 1,485.12 = 470.47 : x
  2. Step 2: Convert to fraction form
    990.10/1,485.12 = 470.47/x
  3. Step 3: Cross multiply
    990.10x = 1,485.12 × 470.47
  4. Step 4: Simplify right side
    990.10x = 698,707.28
  5. Step 5: Solve for x
    x = 698,707.28/990.10
  6. Step 6: Final answer
    x = 705.69

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Double scale
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.