What is the mean for this list of numbers? 17, 19, 21, 23

20.

Step-by-step explanation:

The mean = (sum of the numbers)  / 4   as there are  a total 4 numbers in the list.

Mean = (17+19+21+23) / 4

= 80 / 4

= 20.

step-by-step explanation:

answer

a,b, and d

explanation

a reflection angle is more than

but less than;

an angle that measures

is a reflex angle.(true)

an angle that measures less than

is acute.(true)

provided we are considering angles greater or equal to zero.

an acute angle lies in the range.

an obtuse angle is less than 180° but more than 90°

an angle that measures 300° is obtuse (false)

an angle that measures 65° is an acute angle.(true)