A grocery store manager did a study to look at the relationship between the amount of time (in minutes) customers spend in the store and the amount of money (in dollars) they spend. The results of the survey are shown below. PLAESE ANSWER ALL SUBS A-i its all one question Time 16 8 29 24 8 7 14 19 15 Money 41 29 85 80 42 45 70 71 59 A. Find the correlation coefficient: r= Round to 2 decimal places. B. The null and alternative hypotheses for correlation are: H0: ? r μ ρ = 0 H1: ? ρ μ r ≠ 0 The p-value is:? (Round to four decimal places) C. Use a level of significance of α=0.05α=0.05 to state the conclusion of the hypothesis test in the context of the study? There is statistically insignificant evidence to conclude that a customer who spends more time at the store will spend more money than a customer who spends less time at the store. There is statistically significant evidence to conclude that a customer who spends more time at the store will spend more money than a customer who spends less time at the store. There is statistically significant evidence to conclude that there is a correlation between the amount of time customers spend at the store and the amount of money that they spend at the store. Thus, the regression line is useful. There is statistically insignificant evidence to conclude that there is a correlation between the amount of time customers spend at the store and the amount of money that they spend at the store. Thus, the use of the regression line is not appropriate. D. r2 = (Round to two decimal places) E. Interpret r2? There is a 74% chance that the regression line will be a good predictor for the amount of money spent at the store based on the time spent at the store. There is a large variation in the amount of money that customers spend at the store, but if you only look at customers who spend a fixed amount of time at the store, this variation on average is reduced by 74%. Given any group that spends a fixed amount of time at the store, 74% of all of those customers will spend the predicted amount of money at the store. 74% of all customers will spend the average amount of money at the store. F. The equation of the linear regression line is: ˆy = + x (Please show your answers to two decimal places) G. Use the model to predict the amount of money spent by a customer who spends 16 minutes at the store. Dollars spent =. (Please round your answer to the nearest whole number.) H. Interpret the slope of the regression line in the context of the question? The slope has no practical meaning since you cannot predict what any individual customer will spend. For every additional minute customers spend at the store, they tend to spend on averge $2.24 more money at the store. As x goes up, y goes up. i. Interpret the y-intercept in the context of the question? The average amount of money spent is predicted to be $23.14. If a customer spends no time at the store, then that customer will spend $23.14. The best prediction for a customer who doesn't spend any time at the store is that the customer will spend $23.14. The y-intercept has no practical meaning for this study.
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It is a descriptive summary of a data set. It can be defined by using some of the measures. The central tendencies do not provide information regarding individual data from the dataset. However, they give a summary of the data set. The central tendency or measure of central tendency is a central or typical value for a probability distribution.
Z-Scores
A z-score is a unit of measurement used in statistics to describe the position of a raw score in terms of its distance from the mean, measured with reference to standard deviation from the mean. Z-scores are useful in statistics because they allow comparison between two scores that belong to different normal distributions.
A grocery store manager did a study to look at the relationship between the amount of time (in minutes) customers spend in the store and the amount of money (in dollars) they spend. The results of the survey are shown below.
PLAESE ANSWER ALL SUBS A-i its all one question
Time | 16 | 8 | 29 | 24 | 8 | 7 | 14 | 19 | 15 |
---|---|---|---|---|---|---|---|---|---|
Money | 41 | 29 | 85 | 80 | 42 | 45 | 70 | 71 | 59 |
A. Find the
B. The null and alternative hypotheses for correlation are:
H0: ? r μ ρ = 0
H1: ? ρ μ r ≠ 0
The p-value is:? (Round to four decimal places)
C. Use a level of significance of α=0.05α=0.05 to state the conclusion of the hypothesis test in the context of the study?
- There is statistically insignificant evidence to conclude that a customer who spends more time at the store will spend more money than a customer who spends less time at the store.
- There is statistically significant evidence to conclude that a customer who spends more time at the store will spend more money than a customer who spends less time at the store.
- There is statistically significant evidence to conclude that there is a correlation between the amount of time customers spend at the store and the amount of money that they spend at the store. Thus, the regression line is useful.
- There is statistically insignificant evidence to conclude that there is a correlation between the amount of time customers spend at the store and the amount of money that they spend at the store. Thus, the use of the regression line is not appropriate.
D. r2 = (Round to two decimal places)
E. Interpret r2?
- There is a 74% chance that the regression line will be a good predictor for the amount of money spent at the store based on the time spent at the store.
- There is a large variation in the amount of money that customers spend at the store, but if you only look at customers who spend a fixed amount of time at the store, this variation on average is reduced by 74%.
- Given any group that spends a fixed amount of time at the store, 74% of all of those customers will spend the predicted amount of money at the store.
- 74% of all customers will spend the average amount of money at the store.
F. The equation of the linear regression line is:
ˆy = + x (Please show your answers to two decimal places)
G. Use the model to predict the amount of money spent by a customer who spends 16 minutes at the store.
Dollars spent =. (Please round your answer to the nearest whole number.)
H. Interpret the slope of the regression line in the context of the question?
- The slope has no practical meaning since you cannot predict what any individual customer will spend.
- For every additional minute customers spend at the store, they tend to spend on averge $2.24 more money at the store.
- As x goes up, y goes up.
i. Interpret the y-intercept in the context of the question?
- The average amount of money spent is predicted to be $23.14.
- If a customer spends no time at the store, then that customer will spend $23.14.
- The best prediction for a customer who doesn't spend any time at the store is that the customer will spend $23.14.
- The y-intercept has no practical meaning for this study.
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