Answer:
The t distribution is used, because we have the standard deviation for the sample.
Step-by-step explanation:
When to use the z or the t distribution?
When we have the standard deviation for the population, we use the z distribution.
When we have the standard deviation for the sample, we use the t distribution.
In this question:
We have the standard deviation for the sample, which means that the t distribution is used.
D 14/21 can be reduced by 7 to equal 2/3
The resistance of a material is given by the formula R = ρ*
. Where l is the length and S is the area of the surface calculated with the radius, and ρ is the coefficient that indicates the resistance of a material.
If you keep the lenght and radius, and change the material, ρ will still change and the final resistance (R) will change.
It's 5, because 5 × 7= 35 + 1= 36 ÷ 4= 9.
Hope this helps :)