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Torres, Anicia Lab 8
Generated Apr 16, 2019 by aniciatorres

1. What type of variable is “number of drinks”? Discrete Random Variable

2. Create a histogram of the data and comment on the shape of the distribution. Skewed right

3. Calculate the mean and standard deviation for the number of drinks, and determine the mode. M = 2.0493827 Standard Deviation = 1.55 Mode = 1

4. What is the probability that a randomly selected individual consumes two drinks? P(two drinks) = 66/243 = 0.2716

5. Would it be unusual to observe a randomly selected individual who consumes at least eight drinks? Why P(at least 8 drinks) = 2/243 = 0.00823 Yes, it is unusual.

6. Describe the shape of the sampling distribution of the mean number of drinks if groups of 35 randomly selected individuals are asked about their drinking habits. What is the source of variability in the sampling distribution? 

[Hint: look back at chapter 8].

The sampling distribution is normally distributed, because the sample taken was over 30 randomly selected people. (Standard deviation 1.55 / Square-root of N 35) = 0.261998 The source of variablility is the different drinking habits of each individual. 

7. Construct and interpret a 95% confidence interval for the mean number of drinks. We are 95% confident that the mean number of alcoholic drinks consumed by American adults aged 21 and over is between 1.8535186 and 2.2452469

 

Result 1: Summary Stats drinks   [Info]

Summary statistics:


ColumnnMeanVarianceStd. dev.Std. err.MedianRangeMinMaxQ1Q3
Drinks2432.04938272.40250991.55000320.09943275221111212



Result 2: Histogram drinks   [Info]
Right click to copy