Week 2: STA3163 Intermediate Statistics

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Week 2: STA3163 Intermediate Statistics· Weekly Summary

WEEKLY SUMMARY

Week 2: Weekly Summary

Students, please review the following topics. Post your answers and discuss amongst your peers about
what you learned this week.
1. Which graph is most likely close to having r ::;:: -0.38?

a

b

d

2. The Metro-North station of Greenwich, CT has many commuters but only so many parking spaces.
'
Use t he regression equa t'Ion 0 f •}' = 89.5 + 0.409x t 0 f'rn d th e bes t -pre d'ICt ed num ber 0 f par k'rng spots at
that station when there are 2804 commuters.
3. The systolic blood pressure measurements (in mm Hg) are obtained from the same woman (see
#15, page 532) using her left and right arms. A statistical program is used to run a linear correlation
and regression analysis. The partial results are provided below:

Correlation Results:
Correlation coeff, r: 0.867
Critical r: ±0.878
P-value: 0,057

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Is there sufficient evidence to conclude that there is a linear correlation between right and left arm
systolic blood pressure measurements? Based on the hypothesis test, what can be concluded?
4. A theme park uses roller coaster riders on the "chute" as a predictor of the total number of visitors
to purchase a souvenir when leaving the park. There were 232 riders on the "chute" on a Saturday.
The statistical analysis predicted that there would be 200 riders. Calculate the residual for that data
point.
5. Scientists trying to predict the amount of shooting stars from dusk to midnight are trying to find the
best set of predictors. The researchers hypothesized about what might make good predictors and then
collected data. The following table summarizes these results.

Predictor Variable(s)
Month
Month and day
Month and time
Dav

Arliu<;tF'lrl R2

0.668
0.798
0.856
0.442

Based on the information provided, which set of variables provided the best predictor of the amount of
shooting stars from dusk to midnight?
6. Based upon the scatter plots below, which graph would best be modeled using a linear model with a
positive slope?

a

c

b

d

Please also take this opportunity to discuss the course thus far and make comments about the
Chapters in the textbook.
Please contact me if you have any questions!

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No one has responded to this topic. To be the first respondent, click the Respond link below the topic.

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