Home / 486.82-671.88-388.72

Finding the Fourth Proportional to 486.82, 671.88 and 388.72

Calculator

Solution

The fourth proportional to 486.82, 671.88 and 388.72 is: 536.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.82 : 671.88 = 388.72 : x
  2. Step 2: Convert to fraction form
    486.82/671.88 = 388.72/x
  3. Step 3: Cross multiply
    486.82x = 671.88 × 388.72
  4. Step 4: Simplify right side
    486.82x = 261,173.19
  5. Step 5: Solve for x
    x = 261,173.19/486.82
  6. Step 6: Final answer
    x = 536.49

Related Problems

Find fourth proportional to 243.41, 335.94 and 194.36
Half scale
Find fourth proportional to 973.64, 1,343.76 and 777.44
Double scale
Find fourth proportional to 487.82, 673.26 and 389.72
Similar ratio
Find fourth proportional to 730.23, 1,007.82 and 583.08
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.