Home / 303.80-418.86-289.08

Finding the Fourth Proportional to 303.80, 418.86 and 289.08

Calculator

Solution

The fourth proportional to 303.80, 418.86 and 289.08 is: 398.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    303.80 : 418.86 = 289.08 : x
  2. Step 2: Convert to fraction form
    303.80/418.86 = 289.08/x
  3. Step 3: Cross multiply
    303.80x = 418.86 × 289.08
  4. Step 4: Simplify right side
    303.80x = 121,084.05
  5. Step 5: Solve for x
    x = 121,084.05/303.80
  6. Step 6: Final answer
    x = 398.57

Related Problems

Find fourth proportional to 151.90, 209.43 and 144.54
Half scale
Find fourth proportional to 607.60, 837.72 and 578.16
Double scale
Find fourth proportional to 304.80, 420.24 and 290.08
Similar ratio
Find fourth proportional to 455.70, 628.29 and 433.62
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.