A teacher graded the tests for each of her students. She calculated a mean grade of 80 and a standard deviation of 3. One of her students, Katrina, had a z-score of 2. What grade did Katrina
get on the test?

Katrina got 86 in her test

Step-by-step explanation:

given

mean = 80

standard deviation = 3

z-score = 2

Let score of Katrina = x

Recall z-score is calculated by

z-score = (x-mean) / standard deviation

substitute values and solve for x

2 = (x-80)/3

x-80=6

x = 86

< 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⭐