SWBA T: Distinguish between a parameter and a statistic and define a sampling distribution. ​
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Do Now:​
The variance of a random variable is 204.49. What is the standard deviation of that variable? ​
(A) 13.9 ​
(B) 14.3 ​
(C ) 102.2 ​
(D) 409.0 ​
(E) 41,816.2 ​
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Claim: Mars and Co. reports that their M&M’s candies contain 20% orange.
1. Each of you have a bag of m&m’s. Open your bags and count out a random sample of 50 ​
m&m’s. Disregard (or eat) the rest. ​
2. Out of your sample of 50, determine the proportion (​̂​ ) of orange m&m’s and record this ​
below: ​
̂​ =​ ​
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3. Let’s now, create a class dotplot to investigate the sampling variability of this claim: ​
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4. Describe the shape, center, spread and any unusual values you see. ​
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SWBA T: Distinguish between a parameter and a statistic and define a sampling distribution. ​
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For our investigation:​ ​
a)​ ​ Determine the parameter.
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b)​ ​ Determine the statistic.
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c)​ ​ Is our class dotplot the sampling distribution? Justify your answer.
SWBA T: Distinguish between a parameter and a statistic and define a sampling distribution. ​
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Parameters and Statistics​
A ​parameter​ is a number that describes some ​
characteristic of the population. ​
A ​statistic​ is a number that describes some characteristic ​
of a sample. ​
*R
​ emember s
​ ​ and ​p: st​ atistics come ​
from ​sa​ mples, and ​pa​ rameters come from ​po​ pulations. ​
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Sampling Distribution​
*The sampling distribution of a statistic is the distribution ​
of values taken by the statistic in all possible samples of ​
the same size from the same population. ​
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*If the statistic of the sample is equal to the parameter of ​
the population then it is considered an unbiased estimator ​
of the parameter. ​
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*You want the variability to be "low". Increase the sample ​
size to at least 10% of the population. ​
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SWBA T: Distinguish between a parameter and a statistic and define a sampling distribution. ​
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YOU TRY!!​
Determine whether the underlined value is a parameter or ​
a statistic. ​
a.​In
​ a national survey on substance abuse, ​10%​ of
respondents aged 12 to 17 reported using illicit drugs
within the past month.
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b.​Ty
​ Cobb is one of major league baseball’s greatest
hitters of all time, with a career batting average of
0.366.​
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c.​ A​ study of 6076 adults in public rest rooms (in Atlanta,
Chicago, New York City, and San Francisco) found that
23%​ did not wash their hands before exiting.
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d.​Interview
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of 100 adults 18 years of age or older,
conducted nationwide, found that ​44%​ could state the
minimum age required for the office of US president.