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Finding the Fourth Proportional to 665.63, 918.77 and 491.48

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Solution

The fourth proportional to 665.63, 918.77 and 491.48 is: 678.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.63 : 918.77 = 491.48 : x
  2. Step 2: Convert to fraction form
    665.63/918.77 = 491.48/x
  3. Step 3: Cross multiply
    665.63x = 918.77 × 491.48
  4. Step 4: Simplify right side
    665.63x = 451,550.03
  5. Step 5: Solve for x
    x = 451,550.03/665.63
  6. Step 6: Final answer
    x = 678.39

Related Problems

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Double scale
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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.