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Finding the Fourth Proportional to 145.50, 200.78 and 80

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Solution

The fourth proportional to 145.50, 200.78 and 80 is: 110.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.50 : 200.78 = 80 : x
  2. Step 2: Convert to fraction form
    145.50/200.78 = 80/x
  3. Step 3: Cross multiply
    145.50x = 200.78 × 80
  4. Step 4: Simplify right side
    145.50x = 16,062.40
  5. Step 5: Solve for x
    x = 16,062.40/145.50
  6. Step 6: Final answer
    x = 110.39

Related Problems

Find fourth proportional to 72.75, 100.39 and 40
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Double scale
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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.