1. Calculate the arithmetic mean of the following frequency distribution.
Class 0-40 40 - 80 80 -120 120 - 160 160 - 200
interval
Frequency 12 20
35
30
23

true statements:

a) x + y = y + x   ⇒ commutative property of addition

b) (x * y) * z = x * (y * z) ⇒ associative property of multiplication

d) (x + y) + z = x + (y + z) ⇒ associative property of addition

false statements:

c) x - y = y - x   should be: x - y = - y + x

e) (x - y) - z = x - (y - z) should be: (x - y) - z = x - (y + z)

step-by-step explanation:

here is your mark brainliest

5/20 so 25%

step-by-step explanation: