Home / 286.80-395.78-155.81

Finding the Fourth Proportional to 286.80, 395.78 and 155.81

Calculator

Solution

The fourth proportional to 286.80, 395.78 and 155.81 is: 215.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.80 : 395.78 = 155.81 : x
  2. Step 2: Convert to fraction form
    286.80/395.78 = 155.81/x
  3. Step 3: Cross multiply
    286.80x = 395.78 × 155.81
  4. Step 4: Simplify right side
    286.80x = 61,663.72
  5. Step 5: Solve for x
    x = 61,663.72/286.80
  6. Step 6: Final answer
    x = 215.01

Related Problems

Find fourth proportional to 143.40, 197.89 and 77.90
Half scale
Find fourth proportional to 573.59, 791.55 and 311.61
Double scale
Find fourth proportional to 287.80, 397.15 and 156.81
Similar ratio
Find fourth proportional to 430.19, 593.66 and 233.71
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.