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Finding the Fourth Proportional to 904.84, 1,245.42 and 642.40

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Solution

The fourth proportional to 904.84, 1,245.42 and 642.40 is: 884.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    904.84 : 1,245.42 = 642.40 : x
  2. Step 2: Convert to fraction form
    904.84/1,245.42 = 642.40/x
  3. Step 3: Cross multiply
    904.84x = 1,245.42 × 642.40
  4. Step 4: Simplify right side
    904.84x = 800,057.81
  5. Step 5: Solve for x
    x = 800,057.81/904.84
  6. Step 6: Final answer
    x = 884.20

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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.