Home / 1,287.80-1,776.06-1,007.60

Finding the Fourth Proportional to 1,287.80, 1,776.06 and 1,007.60

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Solution

The fourth proportional to 1,287.80, 1,776.06 and 1,007.60 is: 1,389.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,287.80 : 1,776.06 = 1,007.60 : x
  2. Step 2: Convert to fraction form
    1,287.80/1,776.06 = 1,007.60/x
  3. Step 3: Cross multiply
    1,287.80x = 1,776.06 × 1,007.60
  4. Step 4: Simplify right side
    1,287.80x = 1,789,558.06
  5. Step 5: Solve for x
    x = 1,789,558.06/1,287.80
  6. Step 6: Final answer
    x = 1,389.62

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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.