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Finding the Fourth Proportional to 689.25, 951.18 and 378.75

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Solution

The fourth proportional to 689.25, 951.18 and 378.75 is: 522.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.25 : 951.18 = 378.75 : x
  2. Step 2: Convert to fraction form
    689.25/951.18 = 378.75/x
  3. Step 3: Cross multiply
    689.25x = 951.18 × 378.75
  4. Step 4: Simplify right side
    689.25x = 360,259.43
  5. Step 5: Solve for x
    x = 360,259.43/689.25
  6. Step 6: Final answer
    x = 522.68

Related Problems

Find fourth proportional to 344.63, 475.59 and 189.38
Half scale
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Double scale
Find fourth proportional to 690.25, 952.56 and 379.75
Similar ratio
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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.