I just need the answers to number 4 and 5

Idont get this question can someone me solve it? ** the distance light travels in one second (1 light second) is about 1.86 ×10^5 mi. saturn is about 475 light-seconds from the sun. about how many miles from the sun is saturn..my guess is 8.83* 10^7 you so much

Simplify. 4+3/7x-2-2/7x a. 2-5/7x b. 6-1/7x c. 2+1/7x d. 6+5/7x

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