Home / 450.40-671.78-420.16

Finding the Fourth Proportional to 450.40, 671.78 and 420.16

Calculator

Solution

The fourth proportional to 450.40, 671.78 and 420.16 is: 626.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    450.40 : 671.78 = 420.16 : x
  2. Step 2: Convert to fraction form
    450.40/671.78 = 420.16/x
  3. Step 3: Cross multiply
    450.40x = 671.78 × 420.16
  4. Step 4: Simplify right side
    450.40x = 282,255.08
  5. Step 5: Solve for x
    x = 282,255.08/450.40
  6. Step 6: Final answer
    x = 626.68

Related Problems

Find fourth proportional to 225.20, 335.89 and 210.08
Half scale
Find fourth proportional to 900.80, 1,343.56 and 840.32
Double scale
Find fourth proportional to 451.40, 673.27 and 421.16
Similar ratio
Find fourth proportional to 675.60, 1,007.67 and 630.24
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.