The breaking strengths of cables produced by a certain manufacturer have a mean µ, of 1850 pounds, and a standard deviation of 90 pounds. It is claimed that an improvement in the manufacturing process has increased the mean breaking strength. To evaluate this claim, 21 newly manufactured cables are randomly chosen and tested, and their mean breaking strength is found to be 1893 pounds. Assume that the population is normally distributed. Can we support, at the 0.05 level of significance, the claim that the mean breaking strength has increased? (Assume that the standard deviation has not changed). Carry your intermediate computations to at least three decimal places.

We accept H₀. We do not have argument to keep the claim that the mean breaking strength has increased

Step-by-step explanation:

Normal Distribution

Population Mean   μ₀  = 1850 pounds

Standard Deviation   σ  =  90 pounds

Type of test

Null Hypothesis                         H₀     ⇒    μ  =  μ₀

Alternative Hypothesis            Hₐ      ⇒    μ > μ₀

A one tail test  (right)

n = 21  as    n  < 30  we use t-student table

degree of fredom   20  

t = 2.845

Sample mean   μ = 1893

Then, we compute t statistics

t(s)  =  [ 1893 - 1850 ] / 90/ √n

t(s)  =   43 * 4,583 / 90

t(s)  = 197,069 / 90

t(s)  =  2,190

And we compare t  and  t(s)

t(s)  =  2.190

t =  2.845

Then  t(s)  <  t

We are in the acceptance zone, we accept  H₀

step-by-step explanation:

we can use this expression to calculate the energy gain as a particle moves with a field or the energy loss as it moves against it. (note that it is also used to define the electron-volt, a unit of energy equal to that gained by an electron as it falls through a pd of 1 v, i.e. w = 1 ev = 1.6 10-19 c 1 v = 1.6 10-19j).in fact this expression is really nothing more than the statement that potential is the potential energy per unit charge. in this case, v= w/qis simply stating that the change in potential energy(or work done) per unit charge is equal to the change in potential (or potential difference), v.student questions: uniform electric fields2electron beamcathode+5 kvanode0 v