I am confused on what formula to use

Directions: There are a total of 15 questions answer choice. You will need the following information to answer questions 1 through 4: Data from the year 2017-18 National Health and Nutrition Examination Survey (NHANES) survey includes laboratory measurements on a random sample of 9,254 U.S. adults. Below, please find boxplots and summary statistics of blood lead levels presented separately by reported biological sex (respondents were only given only two options, male or female) at the time of the measurement. Blood Lead Level Measurements U.S. Adults, NHANES 2017-18 Laboratory Cohort Male Female n= 4,557 n= 4,657 x = 1.25 ug/dl x = 0.9 ug/dL s = 1.60 ug/dL s = 0.9 ug/dl 30 Percentiles: Percentiles: Nool The 2.5th : 0.2 2.5th : 0.2 Lead (micrograms/al) 25th : 0.5 25th: 0.4 50th : 0.9 50th: 0.7 75th. : 1.5 led of 75th: 1.1 97.5th. : 4.4 97.5th: 3.3 O Male Female Reported Biological Sex at Time of Survey Please Note: SE (Xmale - Xfemale) =0.03 1 ) Most (roughly the middle 95%) of the 4,657 females had blood lead levels between and a. -0.9 ug/dL ; 2.7 ug /dL b. 0.2 ug /dL; 3.3 ug mg/dL c. 0.4 ug /dL; 1.1 ug /dL d. this cannot be answered without using a standard normal table