Answer:
B
Step-by-step explanation:
It is right
Answer:
a= 63
Step-by-step explanation:
16+11=27
90-27= 63
<h2><u>
Answer with explanation</u>
:</h2>
Let 
be the average life of light bulbs.
As per given , we have
Null hypothesis : 
Alternative hypothesis : 
Since 
is right-tailed and population standard deviation is also known, so we perform right-tailed z-test.
Formula for Test statistic : 
where, n= sample size
= sample mean
= Population mean
=population standard deviation
For 
, we have
Using z-value table , Critical one-tailed test value for 0.06 significance level :
Decision : Since critical z value (1.5548) < test statistic (1.6180), so we reject the null hypothesis .
[We reject the null hypothesis when critical value is less than the test statistic value .]
Conclusion : We have enough evidence at 0.06 significance level to support the claim that the new filament yields a longer bulb life
The answer would be 3 times 10^-5
-- The filler pipe can fill 1/6 of the pool every hour.
-- The drainer pipe can drain 1/10 of the pool every hour.
-- When they're filling and draining at the same time, the filler pipe
will win eventually, because it finishes more of the pool in an hour
than what the drain pipe can finish in an hour.
-- When they're filling and draining at the same time, then every hour,
1/6 of the pool fills and 1/10 of it empties. The difference is (1/6) - (1/10).
To do that subtraction, we need a common denominator.
The smallest denominator that works is 30.
1/6 = 5/30
1/10 = 3/30 .
So in every hour, 5/30 of the pool fills, and 3/30 of the pool empties.
The result of both at the same time is that 2/30 = 1/15 fills each hour.
If nobody notices what's going on and closes the drain pipe, it will take
<em><u>15 hours</u></em> to fill the pool.
If the drain pipe had <em><u>not</u></em> been open, the filler pipe alone could have filled
the pool <em><u>2-1/2 times</u></em> in that same 15 hours. With both pipes open,
1-1/2 pool's worth of water went straight down the drain during that time,
and it was wasted.
I would say that the school should take the cost of 1-1/2 poolsworth out
of Ms. Charles' pay at the rate of $5 a week. I would, but that would
guarantee her more job security than she deserves after pulling a stunt
like that.
I hope this did not take place in California.
