The table below shows the number of tests taken by 30 randomly selected college sophomores?

Question

Number of tests taken/ Number of students

0/12
1/8
2/2
3/3
4 or more/5
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If a student is selected at random, find the probability
a)the student has taken exactly two tests
b)the student has taken at least two tests
c)the student has taken at most three tests
d)the student has taken 3 or fewer tests
e)the student has taken one or two tests.

Answer 1

so we know our sample isze is 30 making n=30.

Lets start with a.

2 students took 2 tests so P = 2/n = 2/30 = 1/15

b) At least 2 tests means you could have take 2 or 3 or 4 or more. Thus,

P = (2+3+5)/n = (10)/30 = 1/3

c) At most three tests means 0, 1, 2, or 3., thus:

P= (12+8+2+3)/n = 25/30 = 5/6

d) If you have taken 3 or fewer tests, that is the same as at most three tests so the answers is the same as c.

3) One or two tests is when using th elogic above.

P = (8+2)/30 = 1/3

Answer 2

a) 2 people have taken 2 tests = 2/30
b) 12 have 0 tests, 8 have 1 = 20 have taken less than 2 meaning 30-20 = 10 have taken at least 2 p =10/30

c) 5 have taken 4 or more 30-5 = 25 = number who have taken at most 3 p =25/30

d) same as c.

e) 8 have 1 and 2 have 2 = 10/30

Answer 3

in basic terms one betta can stay in a 5 gallon tank, no different fis can stay to tell the story in a tank that small. "different than per probability for some very uncommon high priced fish" neons do superb in communities of 7 or greater. bettas are carnivours and could come to a style to devour the neons. additionally, neons could substitute into nippy and tear a bettas fins. tetras are sensative fish, they do no longer deal properly with chemical, organic and organic or temperature shifts. those shifts take place frequently in new and unastablished tanks. and additionally in small tanks, or overstocked tanks, or underfiltered tanks etc.

Answer 4

a) 6.67% 2/30 students
b)33.33% 10/30 students
c)83.33% 25/30 students
d)83.33% 25/30 students
e)33.33% 10/30 students