As the interest rate rises, the cost of a given investment project and businesses invest

As the interest rate rises, the cost of a given investment project  rises and businesses invest less.

Explanation:

The rise in interests will ultimately cause less economic growth. As the interest rate increases, the cost of a project will increase eventually. Even the products that would be used for the project will be subjected to interest hence, the project will become very costly.

People will eventually invest less because they wouldn't be able to pay the interests. Some people might take loans from banks to invest but ultimately they should have a probability of making enough money from the project to return the loan.

Explanation:

economists measure its performance by studying the gross domestic product (GDP)

If GDP goes up, the economy is growing; if it goes down, the economy is contracting.