Answer:
A rational number is said to be closed if the subtracted values and the result obtained are rational. Hence, the equations which supports the condition are :
5.5 - 0.5 = 4
5√4 - √4 = 4√4
Step-by-step explanation:
A.)
√8 - √8 = 0 ; the added values aren't rational and the result, Zero is not rational either.
B.)
5√4 - √4 = 4√4
5(2) - 2 = 2(2)
10 - 2 = 4
All the values in the expression are rational ; hence, it supports the assertion.
C)
5.5 - 0.5 = 4 ; all the values in the expression are rational, hence, it supports the fact.
2√3 - √3 = √3 ; the values in the expression are not rational, hence, it does not meet the condition.
Therefore, only options B and C supports the assertion.
Let me add that I learned most of this from Brainly a user named fichoh :)
Answer:

Step-by-step explanation:
Given

-- City C
--- City K
Required
Determine the 90% confidence interval
This is calculated using:

Calculating 




For a 90% confidence level, the z-score is 1.65. So:

Calculating the standard deviation 

So:


So:


Step 1: Find the slope:

This gives you
, but we need to find b.
To find b, substitute in one (x,y) pair and it doesn't matter which one. I'll go with (4,-2):
![\begin{aligned}-2&=-\dfrac{3}{2}(4)+b\\[0.5em]-2&=-6+b\\[0.5em]4&=b\end{aligned}](https://tex.z-dn.net/?f=%5Cbegin%7Baligned%7D-2%26%3D-%5Cdfrac%7B3%7D%7B2%7D%284%29%2Bb%5C%5C%5B0.5em%5D-2%26%3D-6%2Bb%5C%5C%5B0.5em%5D4%26%3Db%5Cend%7Baligned%7D)
Now take that b-value and plug in into the slope-intercept form:

It's always a good idea to toss in the other x-value from the other point, to make sure it checks out.
Answer:
A
Step-by-step explanation:
I think its awnser A 23.4
The fraction would be 1/10