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Finding the Fourth Proportional to 1,111, 1,533.18 and 645.25

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Solution

The fourth proportional to 1,111, 1,533.18 and 645.25 is: 890.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,111 : 1,533.18 = 645.25 : x
  2. Step 2: Convert to fraction form
    1,111/1,533.18 = 645.25/x
  3. Step 3: Cross multiply
    1,111x = 1,533.18 × 645.25
  4. Step 4: Simplify right side
    1,111x = 989,284.40
  5. Step 5: Solve for x
    x = 989,284.40/1,111
  6. Step 6: Final answer
    x = 890.45

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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.