Answer:
I DONT KNOW IM VERY SORRY CAN JUST PLEASE GIVE ME 5 STARS I WOULD APPRECIATE IT VERY MUCH...
Step-by-step explanation:
The solution of
are 1 + 2i and 1 – 2i
<u>Solution:</u>
Given, equation is 
We have to find the roots of the given quadratic equation
Now, let us use the quadratic formula
--- (1)
<em><u>Let us determine the nature of roots:</u></em>
Here in
a = 1 ; b = -2 ; c = 5

Since
, the roots obtained will be complex conjugates.
Now plug in values in eqn 1, we get,

On solving we get,



we know that square root of -1 is "i" which is a complex number

Hence, the roots of the given quadratic equation are 1 + 2i and 1 – 2i
<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