useAverage 
Get the average of an array reactively.
Usage 
ts
import { useAverage } from '@vueuse/math'
const list = ref([1, 2, 3])
const averageValue = useAverage(list) // Ref<2>ts
import { useAverage } from '@vueuse/math'
const a = ref(1)
const b = ref(3)
const averageValue = useAverage(a, b) // Ref<2>Type Declarations 
typescript
export declare function useAverage(
  array: MaybeRefOrGetter<MaybeRefOrGetter<number>[]>,
): ComputedRef<number>
export declare function useAverage(
  ...args: MaybeRefOrGetter<number>[]
): ComputedRef<number>