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Finding the Fourth Proportional to 875.34, 1,209 and 820.50

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Solution

The fourth proportional to 875.34, 1,209 and 820.50 is: 1,133.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    875.34 : 1,209 = 820.50 : x
  2. Step 2: Convert to fraction form
    875.34/1,209 = 820.50/x
  3. Step 3: Cross multiply
    875.34x = 1,209 × 820.50
  4. Step 4: Simplify right side
    875.34x = 991,984.50
  5. Step 5: Solve for x
    x = 991,984.50/875.34
  6. Step 6: Final answer
    x = 1,133.26

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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.