Answer:
If you multiply any irrational number by the rational number zero, the result will be zero, which is rational. Any other situation, however, of a rational times an irrational will be irrational.
Work=speed times time (my equation to help me figure it out)
ok, 10 men take 84 days to complete a job
therefor, each man completes 1/10 of the job in 84 days
each man does 1/840 of the job per 1 day
so, if we had 5 more, or 15 men
15 times 1/840 times xdays=1 job complete
15/840 times xdays=1job
times both sides by 840/15
xdays=840/15
xdays=56
56 days it would take
Answer:
rearrange them properly to get
x-y=7
-3x+y=12
( by elimination method)
x-y = 7
-3x+y=
(x+ –3x) + (–y+y) = (7+12)
-2x+0= 19
x= -9.5
from eqn(i)
x-y=7
-9.5 - y=7
-y=16.5
y= -16.5
Variance of a continuous random variable X is defined as
Standard deviation is defined as

Hence standard deviation is the positive square root of variance.
Answer:
(a)z=-1
(b)48.5 pounds
(c)61.5 pounds
Step-by-step explanation:

Given:
Mean, μ = 55 pounds
Standard deviation,σ = 6 pounds.
(a)For a dog that weighs 49 pounds.
x=49 pounds
The z-score

(b)When a dog has a z-score of -1.09

The weight of a dog with a z-score of -1.09 is 48.5 pounds.
(c)When a dog has a z-score of 1.09

The weight of a dog with a z-score of 1.09 is 61.5 pounds.