Statistics please assist

Data regarding the standard of air quality at a certain hospital were recorded over a 5-day period. Information concerning the levels of nitrogen dioxide (ppb) was tabulated so as to determine summary statistics for the sample. Unfortunately, some of the calculations were erroneous and needed to be redone. These errors are denoted in the table as missing values being represented by question marks (2'). Determine these missing values. Concentration f of .7: - (ppb) multin mum.. Correct to 1 decimal place, the mean (ppb) of the sample is equal to Select one: 19.5 ppb 20.5 ppb 307.5 ppb 20.9 ppb Suppose it is required to conduct a large sample test of Ho : M = $600 against H1: M # $600 at the 0.05 level of significance. The critical region for this test is Select one: O z > 1.65 O z 1.96 O z 1.65 O z 2.58A sociologist conducted a study of a sample of 60 students to determine how many of each gender smoke marijuana. The results are as follows. Smokes Marijuana Does not Smoke Marijuana Female 8 17 Male 15 20 Given that a randomly selected student is a female, the probability that she smokes marijuana is Select one: 60 8 23 OData regarding the weights (lbs) of 100 toddlers being examined for symptoms related to diabetes are provided in the table below. Calculate the modal weight (correct to one decimal place) of the distribution. Weight of toddler (lbs) Number of toddlers 41 , 49 23 50 58 30 59 67 36 68 , 76 7 77 , 85 4 Select one: 630 lbs 60.2 lbs 60.0 lbs 60.4 lbs