We have to calculate the speed of the runner in mi/h units who completed a 100 yard dash in 9.21 seconds.

**Speed** is defined as the distance covered in unit time.

$\overline{){\mathbf{Speed}}{\mathbf{}}{\mathbf{=}}{\mathbf{}}\frac{\mathbf{distance}\mathbf{}\mathbf{covered}}{\mathbf{time}}}$

To solve this problem, we need to know the following **conversion factors**:

1 mi = 1763 yd

The worlds record in the 100m dash is 9.69s and in the 100 yard dash is 9.21s.

Find the speed in mi/h of the runner who set second record (9.21s).

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