who really know about statistics

0

Godfather Vineyards

Vito Corleone

QNT 275 (I4)

3 January 2017

Dr. Stephen Loro

Table of Contents

1. Introduction 3

Research Problem 3

Purpose of Study 3

Research Question 3

Null and Alternative Hypothesis 3

Alpha Level of Significance 4

Variable Definitions 4

Limitations 4

1. Review of Related Literature 4

Background 4

1. Methodology 4

Research Design 4

Data Collection 5

Data 5

Descriptive Statistics 6

Data Analysis 8

Statistical Methods 8

1. Results 9

2. Conclusions and Recommendations 9

References 11

1. INTRODUCTION

Godfather Vineyards was purchased in Napa Valley CA by Vito Corleone after he won the Powerball Lotto in 2015. The Vineyards are located on 400 acres and produce 100,000 cases of cabernet sauvignon, merlot and chardonnay wine yearly.

Research Problem

Godfather Vineyards may be experiencing low sugar content yield in one of their cabernet sauvignon grape fields which may result in poor quality wine.

Purpose of the Study

The purpose of this research is to inform the owner of Godfather Vineyards, Vito Corleone, of grape field sugar levels so he may make more informed decisions.

Research Question

Is there a significant difference in Godfather Vineyards grape field #1 and grape field #2 as measured by Brix hydrometer sugar levels?

Null and Alternative Hypothesis

Null Hypothesis:

Ho: There is no significant difference in sugar levels between grape field #1 and grape field #2.

Ho: μ1 = μ2.

Alternative Hypothesis:

H1: There is a significant difference in sugar levels between grape field #1 and grape field #2. H1: μ1 ≠ μ2.

Alpha Level of Significance

The alpha level of this research is .01 as determined by the owner Vito Corleone. (α = .01).

Variable Definitions

The measured variable represents the specific gravity of a liquid on the Brix scale using a Brix hydrometer. The Brix hydrometer is calibrated to read sugar levels from 0 to about 30°Brix (also called a sacchrometer). The hydrometer is a graduated cylinder or a long glass tube in which to put the juice of the grapes to test for sugar content. A normal reading from Godfathers prize field #1 is 24 on the Brix scale. The data is quantitative, discrete and ratio.

Limitations

This research was limited to Godfather Vineyards in Napa Valley CA in September 2012. The sample size was limited to 20 selections of 500 gram bunches. The instrument of measurement was the Brix hydrometer.

1. REVIEW OF RELATED LITERATURE

Background

Godfather Vineyards has 400 acres of grape fields located in Napa Valley CA. Two 100 acre fields contain cabernet sauvignon, one 100-acre field contains merlot and one 100-acre field contains chardonnay grapes. Concerned about the sugar yield in the two cabernet fields, Vito Corleone the owner of Godfather Vineyards has requested a test be conducted to compare the sugar yield of both fields. Godfather Vineyards produces an award winning cabernet sauvignon full-bodied wine characterized by high tannin content which serves to provide structure and intrigue while supporting the rich cherry characteristics and the flavor profile of warm spicy vanilla aromas.

1. METHODOLOGY

Research Design

The research design for this study was quasi-experimental random by selection. Samples were randomly chosen from section and row in cabernet grape fields #1 and # 2.

Data Collection

The data collected was 20 random samples, 10 in each field, of 500 grams of grapes from field #1 and field #2 at Godfathers Vineyard in Napa CA. The fields were divided into rows and sections and the sample sections were randomly selected for sampling. Godfather Vineyards foreman Luca Brasi supervised the data sampling.

Data

Data Analysis

The sample size for field # 1 was 10. The mean or average Brix scale was 24. The sample standard deviation was 1.0 and the sample variance was 1.1. The minimum was 22 and the maximum was 25 with a range of 3. The standard error of the mean was .33. The lower 95% confidence limit was 23.34 and the upper 95% confidence limit was 24.65 and with 3 as the range. The skew was -.71 and kurtosis -.45. Coefficient of variation was 4.39%.

The sample size for field # 2 was 10. The mean or average Brix scale was 21.8. The sample standard deviation was 1.9 and the sample variance was 3.7. The minimum was 19 and the maximum was 24 with a range of 5. The standard error of the mean was 1.61. The lower 95% confidence limit was 20.60 and the upper 95% confidence limit was 22.99. The skew was -.45 and kurtosis -1.41 Coefficient of variation was 8.86%. A Goodness of Fit (GOF) test was conducted and determined that both the data sets were normally distributed (p=.057 and p=.157).

Statistical Methods

An independent t-test was used to determine if there was a significant difference between the means of the sugar levels of the two grape fields. The test is appropriate for small samples under 30 whose data sets are normally distributed. MegaStat was used to conduct the analysis.

1. RESULTS

Reject the null hypothesis at the .01 alpha level of significance (p=.005). There is a significant difference in the mean sugar levels of the two grape fields.

1. CONCLUSION AND RECOMMENDATIONS

There appears to be a significant difference between the two grape fields at Godfather Vineyards in Napa Valley CA. The #1 field that produced the award winning cabernet sauvignon wine Bada Bing Bada Boom Private Selection of Godfather’s winery, appears to have a sugar level of 24 similar to the levels in 2008 and 2009. However, # 2 field cabernet sauvignon grape sugar levels are significantly lower than field #1 with mean sugar averages closer to 21. This may affect the quality of the wine fermented from the grapes of #2 field. Clearly, half the cabernet sauvignon wine produce at Godfathers Vineyard may be affected by this condition, which may result in a lower wine ratings and lower profit expectations. Vito Corleone and Luca Brasi will not be pleased with this finding.

Recommend extensive studies initiating a study to determine what may be affecting the sugar content of the grapes in #2 field and perhaps develop techniques to raise the sugar level of the grapes to be more in line with #1 field. Further research is needed.

References

Loro, S. (2017). Course Syllabus QNT 275 Statistics for Decision Making. University of

Phoenix