Home / 151.21-208.66-85.71

Finding the Fourth Proportional to 151.21, 208.66 and 85.71

Calculator

Solution

The fourth proportional to 151.21, 208.66 and 85.71 is: 118.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    151.21 : 208.66 = 85.71 : x
  2. Step 2: Convert to fraction form
    151.21/208.66 = 85.71/x
  3. Step 3: Cross multiply
    151.21x = 208.66 × 85.71
  4. Step 4: Simplify right side
    151.21x = 17,884.25
  5. Step 5: Solve for x
    x = 17,884.25/151.21
  6. Step 6: Final answer
    x = 118.27

Related Problems

Find fourth proportional to 75.61, 104.33 and 42.86
Half scale
Find fourth proportional to 302.42, 417.32 and 171.42
Double scale
Find fourth proportional to 152.21, 210.04 and 86.71
Similar ratio
Find fourth proportional to 226.82, 312.99 and 128.57
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.