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ns test be inconclusive? consider the number of defective items produced on the

ID: 3314136 • Letter: N

Question

ns test be inconclusive? consider the number of defective items produced on the day sh 34)e night shift. The two population variances of the two distributions ar Consi le of the production from 4 days and 4 nights revealed the following rest istributions are equal to 2. A sample owing results: Day-Shift#ofdefects Night shift# of defects 8 10 7 10 8 At a 5% level of significance, is there a difference in the mean num ber of defects per shift? State the null and the alternative hypotheses. b. What is the probability of type I error? c. Is this a one-tailed or a two-tailed test? Why? d. What is the decision rule? e. What is the value of the test statistics? f. What is your decision regarding the null hypothesis? g. What is the p-value? Interpret the result. h. What are the necessary assumptions for this test? a.

Explanation / Answer

SolutioNA:

null hypothesis:

Ho:there are no differences in mean number of defective items produced on the day shift compared to that of night shift

Ho1=2

alternative Hypothesis:

Ha:

Ho:there are differences in mean number of defective items produced on the day shift compared to that of night shift

Ha1:2

Solutionb:

probability of making type 1 error=alpha

alpha=0.05

Solutionc:

its two tail tests

Solutiond:

if p<0.05 reject Null hypopthesis

if p>0.05 fail to reject null hypothesis

Solutione:

perform t etst iN Excel assuming equal variances:

t=2

Solutionf:

t critcial=2.446912

t cal<t crit

2<2.44

Fail ti reject Null hypotthesis

Accept null hypothesis.
Solutiong:

p>0.05

Fail to reject Null hypothesis.

Accept Null hypothesis.

Solutionh:

The observations within each sample must be independent'.

the two populations from which populations are selected must be normal.

the two populations from which populations are selected must have equal varainces.

t-Test: Two-Sample Assuming Equal Variances dayshift nightshift Mean 10 8 Variance 2 2 Observations 4 4 Pooled Variance 2 Hypothesized Mean Difference 0 df 6 t Stat 2 P(T<=t) one-tail 0.046213 t Critical one-tail 1.94318 P(T<=t) two-tail 0.092426 t Critical two-tail 2.446912