Broyles Textbook Practice Exercise
[Name of the Writer]
[Name of the Institution]
Broyles Textbook Practice Exercise
Objective
The objective is to solve the textbook exercises i.e. “Practice Exercise 1” (page 157) and "Practice Exercise 11" (page 180). For the data set listed, we use Excel to extract the mean and standard deviation for the sample of lengths of stay for cardiac patients as in the Practice Exercise 1 and also apply the test to solve the problem Similarly we also use Excel to solve the another exercise.
Practice Exercise 1
Table 1: Descriptive Statistics
Lengths of Stay
Mean
7.7
Standard Error
0.413242339
Median
8
Mode
8
Standard Deviation
2.613574034
Sample Variance
6.830769231
Kurtosis
-0.490362171
Skewness
-0.035014338
Range
11
Minimum
2
Maximum
13
Sum
308
Count
40
Interpretation
The variable Lengths of Stay have platy kurtic behavior as the value of the kurtosis i.e. -0.4903 is less than 3, flatter than a normal distribution with a wider peak. The probability for extreme values is less than for a normal distribution, and the values are wider spread around the mean. Similarly the negative skewness i.e. -0.035014 shows that the Left skewed distribution, most values are concentrated on the right of the mean, with extreme values to the left. Also Length of Stay have smaller standard deviation i.e. 2.61357 therefore smaller standard deviation indicates that there is less dispersion & less variability in the lengths of stay for cardiac patients. Also we see that the average value of 7.7 of the Lengths of stay for cardiac patients. Also we see that maximum 13 no of Lengths of Stay and minimum 2 no of Lengths of Stay (Weiss, 2012).
Table 2: Z-Test
Patients
Lengths of Stay
Mean
20.5
7.7
Known Variance
136
0.170796
Observations
40
40
Hypothesized Mean Difference
1.2
z
6.287036719
P(Z