Business Statistics
M4
| Data Analysis Results: Automobile Insurance Preimun & Household income | ||||||||
| A. Descriptive Statistics | ||||||||
| 1. Categorical Variable: Gender (D1) | ||||||||
| i. & ii. Frequency Distribution and Percentages | ||||||||
| Class | Freq | % | ||||||
| Male | 23 | 51 | ||||||
| Female | 21 | 47 | ||||||
| Did not answer | 1 | 2 | ||||||
| Total | 45 | 100 | ||||||
| iii. Bar Chart | ||||||||
| iv. Pie Chart | ||||||||
| 2. Numerical Variable: Insurance Premium (Q5) | ||||||||
| i. & ii. Frequency Distribution and Percentages | ||||||||
| Class | Freq | % | ||||||
| < $600 | 1 | 14 | 31.11 | |||||
| < $900 | 2 | 9 | 20.00 | |||||
| < $1200 | 3 | 9 | 20.00 | |||||
| < $1500 | 4 | 4 | 8.89 | |||||
| > $1501 | 5 | 9 | 20.00 | |||||
| Total | 45 | 100 | ||||||
| iii. Range | 4.00 | |||||||
| iv. Mean | 2.67 | |||||||
| v. Median | 2.00 | |||||||
| vi. Standard Dev. | 1.50 | |||||||
| Insurance Premium | ||||||||
| Mean | 2.6666666667 | |||||||
| Standard Error | 0.2247332875 | |||||||
| Median | 2 | |||||||
| Mode | 1 | |||||||
| Standard Deviation | 1.5075567229 | |||||||
| Sample Variance | 2.2727272727 | |||||||
| Kurtosis | -1.2524651163 | |||||||
| Skewness | 0.3933671263 | |||||||
| Range | 4 | |||||||
| Minimum | 1 | |||||||
| Maximum | 5 | |||||||
| Sum | 120 | |||||||
| Count | 45 | |||||||
| B. Inferential Statistics | ||||||||
| 1. Insurance Premium vs. Houshold Income: | ||||||||
| The correlation is positive and with a magnitude of.65 statistically significant (Significance F<.05) | ||||||||
| This indicates that if your insurance premium is higher, then it is more likely that your household income is high. | ||||||||
| SUMMARY OUTPUT | ||||||||
| Regression Statistics | ||||||||
| Multiple R | 0.651403561 | |||||||
| R Square | 0.4243265993 | |||||||
| Adjusted R Square | 0.4109388458 | |||||||
| Standard Error | 1.2611364384 | |||||||
| Observations | 45 | |||||||
| ANOVA | ||||||||
| df | SS | MS | F | Significance F | ||||
| Regression | 1 | 50.41 | 50.41 | 31.6951308671 | 0.00000126 | |||
| Residual | 43 | 68.39 | 1.5904651163 | |||||
| Total | 44 | 118.8 | ||||||
| Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% | Lower 95.0% | Upper 95.0% | |
| Intercept | 0.7066666667 | 0.385283546 | 1.834147017 | 0.0735581523 | -0.0703316452 | 1.4836649785 | -0.0703316452 | 1.4836649785 |
| X variable1 | 0.71 | 0.1261136438 | 5.6298428812 | 0.00000126 | 0.4556676015 | 0.9643323985 | 0.4556676015 | 0.9643323985 |
| 2. Construct a 95% confidence interval (C.I.) for "Insurance Premium" | ||||||||
| Using the following formula: | ||||||||
| 95% C.I. | Equals "mean +/- t*Standard Error" | |||||||
| We are using t-score because population standard deviation is unknown | ||||||||
| Using t-Table on page 554 in textbook, df=n-1=45-1=44, Upper tail area=.025, we find t=2.015 | ||||||||
| Mean | 2.67 | |||||||
| Standard Error. | 0.22 | |||||||
| t | 2.015 | |||||||
| 95% C.I. | ||||||||
| Upper limit | 3.11 | |||||||
| Lower limit | 2.23 | |||||||
| In this case we are confident that 95% of similarly constructed intervals will contain the true population mean. | ||||||||
| In other words, we are 95% confident that the true population mean will be between 2.23 and 3.11. | ||||||||
| Further translation: we are 95% confident that in the population, the average automobile insurance premium tends to be between $900 to $1200 based on the sample we have obtained. | ||||||||
| Extra Credit | ||||||||
| EC 1-1. Insurance Premium vs. Purchase Price: | ||||||||
| The correlation is positive and with a magnitude of.73 statistically significant (Significance F<.05) | ||||||||
| This indicates that as your insurance premium rises, more likely your automobile purchase price will increase. | ||||||||
| SUMMARY OUTPUT | ||||||||
| Regression Statistics | ||||||||
| Multiple R | 0.7290544785 | |||||||
| R Square | 0.5315204327 | |||||||
| Adjusted R Square | 0.520625559 | |||||||
| Standard Error | 1.0437851148 | |||||||
| Observations | 45 | |||||||
| ANOVA | ||||||||
| df | SS | MS | F | Significance F | ||||
| Regression | 1 | 53.1520432692 | 53.1520432692 | 48.7862869604 | 0.0000000135 | |||
| Residual | 43 | 46.8479567308 | 1.0894873658 | |||||
| Total | 44 | 100 | ||||||
| Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% | Lower 95.0% | Upper 95.0% | |
| Intercept | 0.9615384615 | 0.289493904 | 3.3214463181 | 0.0018338356 | 0.3777183711 | 1.545358552 | 0.3777183711 | 1.545358552 |
| X variable1 | 0.5994591346 | 0.0858243849 | 6.9847181017 | 0.0000000135 | 0.4263777693 | 0.7725404999 | 0.4263777693 | 0.7725404999 |
| EC 1-2. Purchase Price vs. Household Income: | ||||||||
| The correlation is positive and with a magnitude of.56 statistically significant (Significance F<.05) | ||||||||
| This indicates that as your automobile purchase price increases, more likely the household income will be high. | ||||||||
| SUMMARY OUTPUT | ||||||||
| Regression Statistics | ||||||||
| Multiple R | 0.5597515247 | |||||||
| R Square | 0.3133217694 | |||||||
| Adjusted R Square | 0.2973525082 | |||||||
| Standard Error | 1.3773700403 | |||||||
| Observations | 45 | |||||||
| ANOVA | ||||||||
| df | SS | MS | F | Significance F | ||||
| Regression | 1 | 37.2226262019 | 37.2226262019 | 19.6203046527 | 0.000063938 | |||
| Residual | 43 | 81.5773737981 | 1.8971482279 | |||||
| Total | 44 | 118.8 | ||||||
| Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% | Lower 95.0% | Upper 95.0% | |
| Intercept | 1.1730769231 | 0.3820137158 | 3.0707717407 | 0.0036932859 | 0.4026728523 | 1.9434809939 | 0.4026728523 | 1.9434809939 |
| X variable1 | 0.5016526442 | 0.1132531349 | 4.4294813074 | 0.000063938 | 0.2732559334 | 0.7300493551 | 0.2732559334 | 0.7300493551 |
| EC 2. Construct a 95% confidence interval (C.I.) for "Gender" | ||||||||
| Using the following formula: | ||||||||
| 95% C.I. | Equals "proportion +/- Z*Standard Error" | |||||||
| We create the confidence interval estimate for the population proportion of male.(categorical data) | ||||||||
| We are using z-score; critical value from the standardized norminal distribution. Using z-Table on page 573 in textbook, we find z=1.96 | ||||||||
| Data | ||||||||
| Sample Size | 45 | |||||||
| Number of Male | 23 | |||||||
| Confidence level | 95% | |||||||
| Intermediate Calculations | ||||||||
| Sample Proportion | 0.51 | |||||||
| Standard Error. | 0.07 | |||||||
| Z value | 1.96 | |||||||
| 95% C.I. | ||||||||
| Upper limit | 0.65 | |||||||
| Lower limit | 0.37 | |||||||
| In this case we are confident that 95% of similarly constructed intervals will contain the true population proportion. | ||||||||
| In other words, we are 95% confident that the true population proportion will be between 37% and 65%. | ||||||||
| Further translation: we are 95% confident that in the population, the actual proportion of male tends to be between 37% to 65% based on the sample we have obtained. |
M4
Gender Frequency Distribution
Category
Frequency
Gender Frequency Distribution
M3
Gender Percentages/Proportions
| Q1 | Q2 | Q3 | Q4 | Q5 | Q6 | D1 | D2 | |
| ID | NUMBER OF CAR | NEW OR USED | TYPE OF CAR | PURCHASE PRICE ($) | INSURANCE PREMIUM($) PER 6 MONTH | HOUSEHOLD INCOME ($) | GENDER | AGE GRP |
| CODING RULES | 1=0 2=1 3=2 4=3+ | 1=NEW 2=USED | 1=SEDAN 2=SUV 3=SPORTS CAR 4=NONE 5=OTHER | 1=<15000 2=<25000 3=<35000 4=<45000 5=<55000 6=>54999 | 1=<600 2=<900 3=<1200 4=<1500 5=>1499 | 1=<25000 2=<50000 3=<75000 4=<90000 5=>89999 | 1=FEMALE 2= MALE | 1=15TO24 2=25TO34 3=35TO44 4=45TO54 5=55TO64 6=65+ |
| 1 | 4 | 1 | 5 | 2 | 2 | 4 | 2 | 1 |
| 2 | 2 | 2 | 3 | 1 | 5 | 5 | 1 | 1 |
| 3 | 2 | 2 | 1 | 1 | 1 | 1 | 2 | 2 |
| 4 | 4 | 2 | 1,5 | 2 | 3 | 5 | 1 | 3 |
| 5 | 3 | 1,2 | 1,5 | 2 | 2 | 3 | 1 | 6 |
| 6 | 4 | 1 | 1,2,5 | 4 | 5 | 4 | 1 | 5 |
| 7 | 3 | 1 | 1,2 | 3,6 | 5 | 5 | 2 | 4 |
| 8 | 4 | 2 | 1 | 1 | 1 | 1 | 1 | 2 |
| 9 | 2 | 2 | 1 | 1 | 1 | 1 | 2 | 2 |
| 10 | 1 | 2 | 3 | 1 | 1 | 1 | 1 | 1 |
| 11 | 2 | 1 | 1 | 3 | 3 | 1 | 1 | 1 |
| 12 | 3 | 1 | 1,2 | 2 | 2 | 5 | 1 | 3 |
| 13 | 4 | 2 | 1,3 | 1,2 | 2 | 1 | 2 | 6 |
| 14 | 2 | 1 | 1 | 2 | 3 | 1 | 1 | 1 |
| 15 | 2 | 2 | 1 | 1 | 1 | 1 | 2 | 2 |
| 16 | 4 | 1 | 1,3 | 1,2,3 | 5 | 1 | 1 | |
| 17 | 3 | 1 | 2 | 3 | 3 | 1 | 1 | 2 |
| 18 | 4 | 2 | 1 | 1 | 1 | 2 | 1 | 1 |
| 19 | 4 | 1,2 | 1,2,3 | 3,5 | 5 | 5 | 1 | 1 |
| 20 | 4 | 1,2 | 1,5 | 2,3 | 4 | 4 | 1 | 3 |
| 21 | 1 | 1 | 3 | 3 | 3 | 2 | 2 | |
| 22 | 2 | 2 | 1 | 1 | 1 | 1 | 2 | 1 |
| 23 | 3 | 2 | 3 | 3 | 5 | 1 | 2 | 1 |
| 24 | 4 | 2 | 1 | 1 | 2 | 1 | 2 | 1 |
| 25 | 2 | 1 | 3 | 3 | 3 | 2 | 2 | 2 |
| 26 | 2 | 1 | 1 | 2 | 2 | 1 | 1 | 2 |
| 27 | 2 | 2 | 5 | 1 | 1 | 1 | 2 | 2 |
| 28 | 2 | 1 | 1 | 3 | 3 | 4 | 2 | 2 |
| 29 | 3 | 1 | 1,2 | 3,5 | 5 | 5 | 1 | 3 |
| 30 | 2 | 1 | 3 | 3 | 3 | 2 | 1 | 2 |
| 31 | 4 | 1,2 | 1,3,5 | 1,2,3 | 4 | 4 | 1 | 4 |
| 32 | 1 | 4 | 1 | 1 | 1 | |||
| 33 | 3 | 1 | 1,3 | 2,3 | 4 | 3 | 2 | 5 |
| 34 | 2 | 1 | 1 | 2 | 3 | 1 | 1 | |
| 35 | 4 | 1 | 1,2,5 | 4,5 | 5 | 5 | 1 | 4 |
| 36 | 3 | 1 | 1,3 | 2 | 1 | 3 | 1 | 1 |
| 37 | 2 | 1 | 1 | 1 | 1 | 2 | 2 | |
| 38 | 2 | 1 | 1 | 2 | 1 | 2 | 2 | 2 |
| 39 | 4 | 1 | 1,2 | 6 | 5 | 5 | 2 | 4 |
| 40 | 3 | 1,2 | 1,3 | 2 | 1 | 3 | 2 | 2 |
| 41 | 2 | 2 | 3 | 1 | 2 | 1 | 2 | 1 |
| 42 | 2 | 1 | 1 | 2 | 2 | 1 | 2 | 2 |
| 43 | 3 | 1 | 1,2 | 2 | 4 | 5 | 1 | 4 |
| 44 | 2 | 1 | 5 | 2 | 2 | 3 | 2 | 2 |
| 45 | 4 | 1 | 1 | 2 | 1 | 3 | 2 | 2 |