### Home > INT1 > Chapter 10 > Lesson 10.2.3 > Problem10-106

10-106.

Duncan is testing two types of memory chips (W and Z) for performance and reliability. One test involves a measurement of the maximum electrical current in milliamperes required by the chip when storing and retrieving $14$ different data sets. A lower required current means greater energy efficiency.​

 Data Set: A B C D E F G H I J K L M N Chip W $130$ $130$ $132$ $132$ $133$ $133$ $133$ $134$ $135$ $135$ $135$ $137$ $137$ $137$ checksum $\mathit{1873}$ Chip Z $129$ $131$ $131$ $132$ $132$ $132$ $133$ $133$ $133$ $133$ $134$ $137$ $138$ $140$ checksum $\mathit{1868}$
1. When Duncan was trying to summarize the data, he found the IQR for chip W is larger, but the standard deviation for chip Z was larger. Both are measures of spread. How can they be conflicting? Use combination histogram and boxplots in your explanation.

The IQR can be seen on the boxplot as the length of the box portion.
Does the boxplot for chip W have a larger box than the boxplot for chip Z?
Outliers affect standard deviation, but not the IQR.
Does chip W have more outliers than chip Z?

2. Which chip should Duncan recommend to the manufacturer? Justify your choice.

Which chip has a lower average energy use? Is it consistent?
Does each seem to have it benefits and drawbacks?

Chip Z tends to be more energy efficient. It also has a smaller IQR.
However, it has outliers, so these could indicate a reliability problem.

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