A set of computer science exam scores are normally distributed with a mean of 71.33 points and a standard deviation of
3 points. What proportion of exam scores are between
68 and 77.99 points? You may round your answer to four decimal places.

the solution is h=10 because you add 9 to each side of the equation.

answer: the answer is 127 degrees

< coa = 150 ( given)

as ba and bc are tangents

so oc and oa is perpendicular to cb and ab respectively because in circle normal passes through centre

so in quadrilateral oabc

< coa + < oab + < ocb + < abc = 360

150 +90+90 + < abc = 360

330 + < abc = 360

< abc = 360 -330 = 30

so < abc = 30

⭐dhruv⭐