Answer:
Correct option: B. 90%
Explanation:
The confidence interval is given by:
![CI = [\bar{x} - z\sigma_{\bar{x}} , \bar{x}+z\sigma_{\bar{x}} ]](https://tex.z-dn.net/?f=CI%20%3D%20%5B%5Cbar%7Bx%7D%20-%20z%5Csigma_%7B%5Cbar%7Bx%7D%7D%20%2C%20%5Cbar%7Bx%7D%2Bz%5Csigma_%7B%5Cbar%7Bx%7D%7D%20%5D)
If 
is 190, we can find the value of 
:
Now we need to find the value of 
:
So the value of z is 1.71.
Looking at the z-table, the z value that gives a z-score of 1.71 is 0.0436
This value will occur in both sides of the normal curve, so the confidence level is:
The nearest CI in the options is 90%, so the correct option is B.
Answer:
See attached picture.
Explanation:
See attached picture for explanation.
Answer:
Some of the internal strain energy is relieved.
There is some reduction in the number of dislocations.
The electrical conductivity is recovered to its precold-worked state.
The thermal conductivity is recovered to its precold-worked state
Explanation:
The process of the recovery of a cold-worked material happens at a very low temperature, this process involves the movement and annihilation of points where there are defects, also there is the annihilation and change in position of dislocation points which leads to forming of the subgrains and the subgrains boundaries such as tilt, twist low angle boundaries.
Answer:
It is because constraints applied automatic by the software (CAD) are supposed to control relationships and geometry between lines, arcs and circles while those manually added are supposed to control the geometry to behave in the manner the user likes the sketch to appear when drawing.
Explanation:
CAD software enables creating sketches using the program by automatic allowing geometric constraints to perform the tasks.Geometry in lines, circles, and other geometric features show collaborating relation that facilitate sketching in the program.For example, two end points appear to make lines remain perpendicular.Other geometric constraints are parallel, and equal.However, the user can manually apply geometric constraints to a sketch to force the geometry in a manner that is suitable to the sketch drawn.That is why a user must manually apply others.
Answer:
The heat of the arc melts the surface of the base metal and the end of the electrode. The electric arc has a temperature that ranges from 3,000 to 20,000 °C
Explanation:
Welding fumes are complex mixtures of particles and ionized gases.
