Answer:
See below
Explanation:
<u>Check One-Sample T-Interval Conditions</u>
Random Sample? √
Sample Size ≥30? √
Independent? √
Population Standard Deviation Unknown? √
<u>One-Sample T-Interval Information</u>
- Formula -->
- Sample Mean -->
- Critical Value -->
(given 
degrees of freedom at a 95% confidence level) - Sample Size -->
- Sample Standard Deviation -->
<u>Problem 1</u>
The critical t-value, as mentioned previously, would be , making the 95% confidence interval equal to 
This interval suggests that we are 95% confident that the true mean levels of lead in soil are between 381.5819 and 398.9181 parts per million (ppm), which satisfies the EPA's regulated maximum of 400 ppm.
Answer:
The probable grain-coarsening mechanism is : Ideal grain growth mechanism
( 
- 
= kt )
Explanation:
The plot attached below shows the time dependence of the growth of grain.
The probable grain-coarsening mechanism is : Ideal grain growth mechanism
the ideal growth follows this principle = 
= kt
d = final grain size
= initial grain size
k = constant ( temperature dependent )
t = 0
Solution :
Using the data table for refrigerant-134a at P = 120 psia
∴ 
For pressure, P = 20 psia
Change in temperature, 
Now we find the quality,
The final energy,
Change in internal energy
= 38.09297-40.5485
= -2.4556
Answer:
c) can be made with a variety of surface finishes.
Explanation:
The missing options are;
When it comes to concrete work in construction, the concrete can be cast either in-situ or in form of pre-cast concrete.
Now in-situ concrete means concrete done on the construction site being built while pre cast concrete simply means concrete cast outside in a factory or yard and brought to site to mount.
These pre cast concrete could have different surface finishes as required as this is one of it's advantages over in situ because there is a lot of space and room to have the desired concrete finish.
a) are typically manufactured on site and then hoisted into place.
b) cannot be fiber-reinforced.
c) can be made with a variety of surface finishes.
d) never include insulation.
e) often are unreinforced.
