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Finding the Fourth Proportional to 660.40, 910.38 and 485.44

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Solution

The fourth proportional to 660.40, 910.38 and 485.44 is: 669.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.40 : 910.38 = 485.44 : x
  2. Step 2: Convert to fraction form
    660.40/910.38 = 485.44/x
  3. Step 3: Cross multiply
    660.40x = 910.38 × 485.44
  4. Step 4: Simplify right side
    660.40x = 441,934.87
  5. Step 5: Solve for x
    x = 441,934.87/660.40
  6. Step 6: Final answer
    x = 669.19

Related Problems

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Half scale
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Double scale
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Similar ratio
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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.