In preparation for upcoming wage negotiations with the union, the managers for the Bevel Hardware Company want to establish the time require

Question

In preparation for upcoming wage negotiations with the union, the managers for the Bevel Hardware Company want to establish the time required to assemble a kitchen cabinet. A first line supervisor believes that the job should take 40 minutes on average to complete. A random sample of 120 cabinets has an average assembly time of 42 minutes with a standard deviation of 8 minutes. Is there overwhelming evidence to contradict the first line supervisors belief at a 0.05 significance level

in progress 0
Evelyn 4 months 2021-10-08T13:30:31+00:00 1 Answer 0 views 0

Answers ( )

    0
    2021-10-08T13:31:45+00:00

    Answer:

    t=\frac{42-40}{\frac{8}{\sqrt{120}}}=2.739  

    The p value for this case would be given by:

    p_v =2*P(z>2.739)=0.0616  

    Since the p value is lower than the significance level of 0.05 we have enough evidence to conclude that the true mean for the assembly time is significantly different from 40 minutes.

    Step-by-step explanation:

    Information provided

    \bar X=42 represent the sample mean for the assembly time

    s=8 represent the sample deviation

    n=120 sample size  

    \mu_o =40 represent the value to verify

    \alpha=0.05 represent the significance level

    t would represent the statistic

    p_v represent the p value for the test

    System of hypothesis

    We want to conduct a hypothesis in order to see if the true mean is equal to 40 minutes or not, the system of hypothesis would be:  

    Null hypothesis:\mu =40  

    Alternative hypothesis:\mu \neq 40  

    The statistic for this case is given by:

    z=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}} (1)  

    Replacing the info given we got:

    t=\frac{42-40}{\frac{8}{\sqrt{120}}}=2.739  

    The p value for this case would be given by:

    p_v =2*P(z>2.739)=0.0616  

    Since the p value is lower than the significance level of 0.05 we have enough evidence to conclude that the true mean for the assembly time is significantly different from 40 minutes.

Leave an answer

45:7+7-4:2-5:5*4+35:2 =? ( )