In a recent study on world​ happiness, participants were asked to evaluate their current lives on a scale from 0 to​ 10, where 0 represents the worst possible life and 10 represents the best possible...

In a recent study on world​ happiness, participants were asked to evaluate their current lives on a scale from 0 to​ 10, where 0 represents the worst possible life and 10 represents the best possible life. The responses were normally​ distributed, with a mean of

and a standard deviation of

Answer parts

below.

​(a) Find the probability that a randomly selected study​ participant's response was less than

The probability that a randomly selected study​ participant's response was less than 4 is