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Finding the Fourth Proportional to 928.38, 1,280.80 and 555.36

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Solution

The fourth proportional to 928.38, 1,280.80 and 555.36 is: 766.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    928.38 : 1,280.80 = 555.36 : x
  2. Step 2: Convert to fraction form
    928.38/1,280.80 = 555.36/x
  3. Step 3: Cross multiply
    928.38x = 1,280.80 × 555.36
  4. Step 4: Simplify right side
    928.38x = 711,305.09
  5. Step 5: Solve for x
    x = 711,305.09/928.38
  6. Step 6: Final answer
    x = 766.18

Related Problems

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Half scale
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Double scale
Find fourth proportional to 929.38, 1,282.18 and 556.36
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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.