Listed below are the lead concentrations (in mg/g) measured in different samples of a medicine. what do the results suggest about the safety of this medicine? what do the decimal values of the listed amounts suggest about the precision of the measurements?

There is not enough information for any meaningful conclusion.

They are rounded to one half unit measurements.

Because lead causes significant public health problems, a number of federal agencies have issued advisory standards or enforceable regulations that set lead levels in different media. 

Six amino acids have side chains that are polar but not charged. these are serine (ser), threonine (thr), cysteine (cys), asparagine (asn), glutamine (gln), and tyrosine (tyr). these amino acids are usually found at the surface of proteins, as discussed in the proteins 2 module.