Instruction 18-11
Recently, a University Switched to a New Type

question 21

Short Answer

Instruction 18-11
Recently, a university switched to a new type of computer-based registration. The registrar is concerned with the amount of time students are spending on the computer registering under the new system. She decides to randomly select eight students on each of the 12 days of the registration and determine the time each spends on the computer registering. The range, mean, and standard deviation of the times required to register are in the table that follows.
$\begin{array}{llll}\text { Day } &\text { Range } & \text { Mean }&\text { Std. Dev }\\\hline1 & 10 & 5.250 & 3.4949 \\2 & 31 & 15.250 & 10.3060 \\3 & 13 & 20.375 & 4.9262 \\4 & 21 & 22.875 & 8.3911 \\5 & 35 & 8.500 & 11.3767 \\6 & 18 & 7.875 & 6.9372 \\7 & 25 & 11.250 & 8.5815 \\8 & 30 & 7.875 & 9.5235 \\9 & 17 & 10.250 & 6.3640 \\10 & 22 & 9.500 & 7.8740 \\11 & 27 & 7.875 & 8.7086 \\12 & 26 & 12.875 & 9.3723\end{array}$

-Referring to Instruction 18-11,an R chart is to be constructed for the time required to register.The upper control limit for this data set is _______

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Definitions:

Null Hypothesis

A default statement that there is no effect or no difference, used as a starting point for statistical testing.

Main Effects

The individual impacts of multiple independent variables on a dependent variable in an experimental setting, rephrased from main effect.

Factorial Design

An experimental strategy where two or more factors are varied, allowing researchers to study their individual effects and interactions.

Null Hypothesis

A hypothesis that assumes no significant difference or effect within the context of the study.