Home / 185.70-278.10-139.80

Finding the Fourth Proportional to 185.70, 278.10 and 139.80

Calculator

Solution

The fourth proportional to 185.70, 278.10 and 139.80 is: 209.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    185.70 : 278.10 = 139.80 : x
  2. Step 2: Convert to fraction form
    185.70/278.10 = 139.80/x
  3. Step 3: Cross multiply
    185.70x = 278.10 × 139.80
  4. Step 4: Simplify right side
    185.70x = 38,878.38
  5. Step 5: Solve for x
    x = 38,878.38/185.70
  6. Step 6: Final answer
    x = 209.36

Related Problems

Find fourth proportional to 92.85, 139.05 and 69.90
Half scale
Find fourth proportional to 371.40, 556.20 and 279.60
Double scale
Find fourth proportional to 186.70, 279.60 and 140.80
Similar ratio
Find fourth proportional to 278.55, 417.15 and 209.70
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.