The Impact of Music on the Growth of Plants - Statistics Project Example

c. The level of measurement of the height of the plants follows a ratio scale since all the heights are distinct numbers.
d. The population distribution should be normally distributed since the plants in the two groups are selected at random. There is no selection bias involved.
e. Josh is making use of simple random sampling for his study.

Part 2: Descriptive Statistics
a. Normal Distribution
i. The histograms for plant heights without music exposure and with music exposure are designed separately since they were subjected to different conditions. The histograms are shown in Figures 2.1 and 2.2 respectively. From these histograms, it can be observed that in both cases the curves are bell-shaped hence indicating that the data is normally distributed (Basic Tools for Process Improvement).

Figure 2.1: Histogram of plants without music exposure
Figure 2.2: Histogram of plants with music exposure
ii. The mean, median, and mode can be calculated for the entire data as well as the two groups separately (Descriptive Statistics). The values obtained are tabulated in Table 2.1.

Table 2.1: Measures of Central Tendency
Measure Plants without music exposure Plants with music exposure All plants
Mean 64.25 68.925 66.5875
Median 64 69 66
Mode 64 69 66

b. Variation
The measures of variation are similarly calculated as shown in Table 2.2.

Table 2.2: Measures of Variation
Measure Plants without music exposure Plants with music exposure All plants
Range 14 14 18
Standard Deviation 3.2 3.415 4.043

c. Outliers
For the plants without music exposure, the scores of 71 and 72 would be outliers. For plants with music exposure, the 2 scores of 62 and the score of 76 would be outliers.

d. Corrections
For corrections, an outlier analysis should be run to determine the root cause of the outliers. If an assignable cause is identified, the outliers can be dropped from the analysis. Read More