Home / 1,678.16-2,315.40-979.40

Finding the Fourth Proportional to 1,678.16, 2,315.40 and 979.40

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Solution

The fourth proportional to 1,678.16, 2,315.40 and 979.40 is: 1,351.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,678.16 : 2,315.40 = 979.40 : x
  2. Step 2: Convert to fraction form
    1,678.16/2,315.40 = 979.40/x
  3. Step 3: Cross multiply
    1,678.16x = 2,315.40 × 979.40
  4. Step 4: Simplify right side
    1,678.16x = 2,267,702.76
  5. Step 5: Solve for x
    x = 2,267,702.76/1,678.16
  6. Step 6: Final answer
    x = 1,351.30

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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.