Question 1

Life tests on a part give a population mean value of 3000 hours and a population standard deviation of 200 hours. If the data are normally distributed, what percent of the parts are above 3300 hours.

Accepted Answer

0.0668

Question 2

The peakedness of the data is called:

Accepted Answer

Peakedness is commonly referred to as kurtosis. Skewness refers to the asymmetry of the data, lepto is a term for describing a distribution with low kurtosis, and modal refers to the most frequently occurring value in a distribution.

Question 3

The distance between adjacent midpoints is called:

Accepted Answer

The distance between adjacent midpoints is called an interval. It represents the distance or range between two values on a number line or in a set of data.

Question 4

The type of frequency distribution which is most commonly found in quality work is:

Accepted Answer

Normal frequency distribution is commonly found in quality work as it represents a bell-shaped curve which indicates that most values fall near the mean, with fewer values further from the mean. This is often seen in quality control where there is a target mean value and deviations from that value are of interest.

Question 5

Ungrouped data collected on the time to perform a clerical operation are 3.0, 7.0, 3.0, and 6.0 minutes. Determine the average, median, mode, and sample standard deviation. It is NOT necessary to show your work. Use the function keys on your
calculator. $\begin{array} { l  }& \text { Answers }\
 \text {Average }&\_\_\_\_\_ \
 \text {Range }&\_\_\_\_\_ \
 \text { Median}&\_\_\_\_\_ \
 \text {Mode }&\_\_\_\_\_ \
 \text { Sample Standard Deviation}
\end{array}$

Accepted Answer

The answer of Ungrouped data collected on the time to...

Question 6

The extreme or limit values of a cell are called:

Accepted Answer

The extreme or limit values of a cell are called boundaries. The term "midpoints" refers to the middle value between two points, "interval" refers to the range between two values, and "tallies" are marks made to record a count.

Question 7

The number of cells in a frequency distribution is between:

Accepted Answer

The answer should be D because it is the only option that encompasses a wide range of values for the number of cells in a frequency distribution. Option A and B are too narrow, and option C is too high. Thus, option D is the best choice as it includes all other answer options as part of its range.

Question 8

If the range or 400 observed values has a high of 360 kg and a low of 295 kg, the best cell interval is:

Accepted Answer

To find the best cell interval, we need to consider factors such as the overall range of the data and the desired number of intervals. A general rule of thumb is to have between 5-20 intervals.

In this case, the range of the data is 360 kg - 295 kg = 65 kg. To get a cell interval that is easy to work with mathematically and visually, we should choose a number that divides evenly into the range.

Out of the given choices, only 5 divides evenly into 65 (65/5 = 13). Therefore, the best choice would be 5. This would give us a total of 13 intervals, which is a reasonable number for 400 observed values.

Question 9

A milk bottle has a lower specification of 4.0 liters and a standard deviation of 0.02 liters. The data are normally distributed. If 2.5% of the data is to be below the lower specification, where should the process center be located?

Accepted Answer

The answer of A milk bottle has a lower specification...

Question 10

A variable is:

Accepted Answer

A variable is a measurable quality characteristic, such as weight, height, temperature, or age. It can take on different values, and its value can change over time or from one individual or object to another. It is not a "good-bad" type characteristic, which would be binary, or synonymous with attribute, which is another statistical term used to describe a characteristic of a population or sample.

Question 11

The product of 3.10 x .015 is:

Accepted Answer

3.10 x .015 = 0.0465, which is closest to choice A, 0.047.

Question 12

When an accurate measure of the dispersion is desired use the:

Accepted Answer

The standard deviation is the best choice because it takes into account all the data points in the calculation, is sensitive to outliers, and provides a more precise measure of dispersion than the range or mean deviation. The mode is not a measure of dispersion, but rather a measure of central tendency.

Question 13

When a quick measure of the dispersion is desired, use the:

Accepted Answer

The range provides a quick and easy measure of dispersion by simply subtracting the smallest value from the largest value in the dataset. While it may not provide a complete picture of variability, it can be useful for a quick comparison between datasets. The mean deviation and standard deviation are more comprehensive measures of dispersion, but are more time-consuming to calculate. The mode is a measure of central tendency, not dispersion.

Question 14

Given the frequency distribution, sketch a relative cumulative frequency histogram.Label the axis. (Cell midpoint, Frequency) = (1.0, 3) (4.0, 5) and (7.0, 4)
$\begin{array} { |l|l|l|l|l|l|l| l| }
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\hline \quad&\quad&\quad&\quad&\quad&\quad&\quad&\quad\
\hline \quad&\quad&\quad&\quad&\quad&\quad&\quad&\quad\
\hline \quad&\quad&\quad&\quad&\quad&\quad&\quad&\quad\
\hline \quad&\quad&\quad&\quad&\quad&\quad&\quad&\quad\
\hline \quad&\quad&\quad&\quad&\quad&\quad&\quad&\quad\
\hline \quad&\quad&\quad&\quad&\quad&\quad&\quad&\quad\
\hline \quad&\quad&\quad&\quad&\quad&\quad&\quad&\quad\
\hline 
\end{array}$

Accepted Answer

The answer of Given the frequency distribution, sketch a relative...

Quiz 5: Fundamentals of Statistics