Home / 1,378.74-1,899.45-1,128.60

Finding the Fourth Proportional to 1,378.74, 1,899.45 and 1,128.60

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Solution

The fourth proportional to 1,378.74, 1,899.45 and 1,128.60 is: 1,554.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,378.74 : 1,899.45 = 1,128.60 : x
  2. Step 2: Convert to fraction form
    1,378.74/1,899.45 = 1,128.60/x
  3. Step 3: Cross multiply
    1,378.74x = 1,899.45 × 1,128.60
  4. Step 4: Simplify right side
    1,378.74x = 2,143,719.27
  5. Step 5: Solve for x
    x = 2,143,719.27/1,378.74
  6. Step 6: Final answer
    x = 1,554.84

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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.