PMC:7547912 / 10884-11151 JSONTXT

{"project":"LitCovid-sentences","denotations":[{"id":"T60","span":{"begin":90,"end":98},"obj":"Sentence"},{"id":"T61","span":{"begin":100,"end":124},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"{\\sigma}_{X_2}$$\\end{document}σX1,σX2 are the standard deviation of X1, X2 respectively.\n\nAnalysis\n\nComparative study of AQI\nIn the present investigation, the AQI level was at its highest peak on year starting among all of the four studied sites i.e., 443 in site 1, "}