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Finding the Fourth Proportional to 685.16, 945.53 and 390.44

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Solution

The fourth proportional to 685.16, 945.53 and 390.44 is: 538.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.16 : 945.53 = 390.44 : x
  2. Step 2: Convert to fraction form
    685.16/945.53 = 390.44/x
  3. Step 3: Cross multiply
    685.16x = 945.53 × 390.44
  4. Step 4: Simplify right side
    685.16x = 369,166.05
  5. Step 5: Solve for x
    x = 369,166.05/685.16
  6. Step 6: Final answer
    x = 538.80

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.