Videocassette Recorder (VCR) Tapes Are Designed So That Users Can

question 7

Essay

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 utilising the new technology were used in an experiment. The tapes were used to record and re-record programs until they began to deteriorate. The number of re-recordings is assumed to be normally distributed. It is generally accepted that the number of re-recordings should exceed 55. Any tapes that do not meet this criterion are considered to be unacceptable. The number of re-recordings were observed and shown in the accompanying table. $$\begin{array} { | c cc | cc c | } \hline { \text { Old-style tapes } } &&& { \text { New-technology tapes } } \\\hline 60 & 61 & 48 & 68 & 70 & 58 \\\hline 51 & 46 & 66 & 74 & 72 & 69 \\\hline 66 & 63 & 61 & 77 & 73 & 49 \\\hline 73 & 55 & 71 & 59 & 66 & 61 \\\hline 71 & 49 & 76 & 52 & 58 & 59 \\\hline 47 & 56 & 55 & 66 & 51 & 49 \\\hline 60 & 62 & 64 & 62 & 59 & 57 \\\hline 52 & 51 & 63 & 51 & 56 & 66 \\\hline 64 & 68 & 52 & 50 & 55 & 76 \\\hline 47 & 55 & 58 & 63 & 68 & 78 \\\hline\end{array}$$ Estimate with 90% confidence the difference in the mean number of re-recordings between the old and new tapes.

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Definitions:

Neurotransmitter Systems

Networks within the brain that use specific neurotransmitters to communicate and regulate various physiological processes and behaviors.

Schizophrenic Brain

Characterized by alterations in the structure and function of the brain associated with schizophrenia, including changes in neurotransmitter systems and brain volume.

Transcranial Magnetic Stimulation

A noninvasive procedure that uses magnetic fields to stimulate nerve cells in the brain to improve symptoms of certain neurological and psychiatric disorders.

Schizophrenia

A long-term mental disorder characterized by distorted thoughts, perceptions, emotions, language, sense of self, and behavior.