in a school every student has to participate in at least one of the activities at letters on music in a class of 50 students 30 participated in athletics and 25 participated in music how many students participated in only one activityin our school ​

The mean finish time was 185.52 with a standard deviation of 0.327 minute. the winning car driven by chris finished in 185.13. the previous year race had a mean finish time of 110.3 with a standard deviation of 0.106. the winning car that year driven by karen finished in 110.13 minutes. find their respective z-scores. chris - z-score karen “- z-score