Question:Following is a problem description. For allhypothesis tests, you MUST show all7 stepsand use theP-VALUE METHODto make your decision.For confidence intervals, there are not specific steps, but there is aspecific Excel tool for each interval.They should not be done by-hand for this set, nor should you simply use Excel formulas to use it as a calculator.

Videocassette recorder (VCR) tapes are designed so that users can repeatedly record new material over old material. However, after a number of re-recordings the tape begins to deteriorate. A VCR tape manufacturer is experimenting with a new technology, which hopefully will produce longer-lasting tapes. Thirty of the old-style tapes and 30 utilizing the new technology were used in an experiment. The tapes were used to record and rerecord programs until they began to deteriorate. The number of re-recordings were observed and shown in the accompanying table.It is generally accepted that the number of re-recordings should exceed 55. Any that do not are considered to be unacceptable.(NOTE:This does not mean you throw them out! They are part of the sample and we expect some to be unacceptable ... that is why we are testing!)The number of re-recordings is assumed to be normally distributed.

NOTE: use ONLY the P-value method for hypothesis tests.

Old-Style Tapes: 60 51 66 73 71 47 60 52 64 47 61 46 63 55 49 56 62 51 68 55 48 66 61 71 76 55 64 63 52 58

New Technology Tapes: 68 74 77 59 52 66 62 51 50 63 70 72 73 66 58 51 59 56 55 68 58 69 49 61 59 49 57 66 76 78

Question:Estimate with 90% confidence the difference in the mean number of re-recordings between the old and new tapes and interpret the interval.