Before determining the amount of Na2CO3 in a sample, you decide to
check your procedure by analyzing a sample known to
be 98.76% w/w Na2CO3. Five replicate determinations
of the %w/w Na2CO3 in the standard gave the
following results.
98.71% 98.59% 98.62% 98.44% 98.58%
Using α = 0.05, is there any evidence that the analysis is
giving inaccurate results?​

Answer is in the photo. I couldn't attach it here, but uploaded it to a file hosting. link below! Good Luck!

cutt.ly/UzDInDt

Hello there!

Let's first consider. A wheel and axle would consists of when to parts, of ever more, would do a certain thing, and then change it. 

So, when looking at your options above, I would consider the option of "the man turning the door nob". The reason to why this would be the answer would be because in the door nob, they're two or more materials that would together do something, to either shut the door, and to close it also.

Your "the man opening/closing the door".

I hope this helps you!