Home / 211.80-317.93-90.15

Finding the Fourth Proportional to 211.80, 317.93 and 90.15

Calculator

Solution

The fourth proportional to 211.80, 317.93 and 90.15 is: 135.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    211.80 : 317.93 = 90.15 : x
  2. Step 2: Convert to fraction form
    211.80/317.93 = 90.15/x
  3. Step 3: Cross multiply
    211.80x = 317.93 × 90.15
  4. Step 4: Simplify right side
    211.80x = 28,661.39
  5. Step 5: Solve for x
    x = 28,661.39/211.80
  6. Step 6: Final answer
    x = 135.32

Related Problems

Find fourth proportional to 105.90, 158.97 and 45.08
Half scale
Find fourth proportional to 423.60, 635.86 and 180.30
Double scale
Find fourth proportional to 212.80, 319.43 and 91.15
Similar ratio
Find fourth proportional to 317.70, 476.90 and 135.23
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.