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Finding the Fourth Proportional to 904.20, 1,242.96 and 815.10

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Solution

The fourth proportional to 904.20, 1,242.96 and 815.10 is: 1,120.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    904.20 : 1,242.96 = 815.10 : x
  2. Step 2: Convert to fraction form
    904.20/1,242.96 = 815.10/x
  3. Step 3: Cross multiply
    904.20x = 1,242.96 × 815.10
  4. Step 4: Simplify right side
    904.20x = 1,013,136.70
  5. Step 5: Solve for x
    x = 1,013,136.70/904.20
  6. Step 6: Final answer
    x = 1,120.48

Related Problems

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Half scale
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Similar ratio
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.