arrayOfEvenNumbers.js

const arrayOfEvenNumbers = (numbers) => {
	const arrayForEventualResults = []

	for (let index = numbers.length - 1; index >= 0; index--) {
		// check if this is an even index
		if (index % 2 === 0) {
			// check if the number at this index is evem
			const numberAtCurrentIndex = numbers[index]
			if (numberAtCurrentIndex % 2 === 0) {
				// add the number to the `arrayForEventualResults`
				arrayForEventualResults.push(numberAtCurrentIndex)
			}
		}

	}
	// after the above transversal,
	// find the average /mean
	console.log(arrayForEventualResults)
	return arrayForEventualResults.reduce((a, b) => a + b, 0) / arrayForEventualResults.length

}

console.log('input 11, 21, 32, 34, 36, 37, 41, 42, 52 -> output average ->',  arrayOfEvenNumbers([11, 21, 32, 34, 36, 37, 41, 42, 52]))