To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyses reviews to verify trustworthiness.
This was very easy to assemble. I read the reviews about the ball being too small. I had no problems getting the ball to inflate to the correct size when using an air compressor. My husband added the air a little bit at a time until we got the correct size. I purchased this for my classroom and my students love it.