Many people use scanners to read documents and store them into pdf file. To help determine which brand of scanner to buy, a student conducts an experiment in which 8 different documents were scanned by each of the two scanners that he is interested in. He records the number of errors made by each. Can he infer that Brand A (the more expensive scanner) is better than Brand B

The data is missing in the question. The data is provided below :

Document : 1     2      3      4      5     6      7      8

Brand A       17  29    18    14    21   25    22    29

Brand B       21  38    15    19    22   30    31   37

Solution :

State of the hypothesis of the null hypothesis and alternate hypothesis.

Null hypothesis :

Alternate hypothesis :

These hypothesis is a one tailed test. The null hypothesis will get rejected when the mean difference between the sample means is very small.

Significance level = 0.05

Therefore the standard error is :  

                                                         = 3.602

And the degree of freedom, DF = 14

 = -1.319

Here, = standard deviation of the sample 1

        = standard deviation of the sample 2

          = size of the sample 1

        = size of the sample 2

          = mean of the sample 1

        = mean of the sample 2      

          d = the hypothesis difference between the population mean

The observed difference in a sample means t static of -1.32. From t distribution calculator to determine P() = 0.1042  

Since the P value of 0.1042 is greater than significance level o 0.05, we therefore cannot reject the null hypothesis.

But from the test, we have no sufficient evidence that supports that Brand A is better than Brand B.      

its a trick question

step-by-step explanation:

dogs love water, just turn on the hose and it will run in circles chasing the water all day : )