### mphToKmph

Convert miles/hour to kilometers/hour.

Multiply the constant of proportionality with the argument.

```js
const mphToKmph = (mph) => 1.6093440006146922 * mph;
```

```js
mphToKmph(10); // 16.09344000614692
mphToKmph(85.9); // 138.24264965280207
```