1
Determine whether the number described is a statistic or a parameter.
In a recent poll, 57% of the respondents supported a school bond issue.
Statistic
What is the difference between "Frequency" and "Relative Frequency".
"Frequency" is the number of times a piece of data occurs in a data set.
"Relative Frequency" is the proportion of certain observations in a data set.
Find The Mean Median and Mode(s) of Data Set:
1.2, 1.5, 1.7, 2.1, 98.6
Mean = 21.02
Median = 1.70
Mode = None
If you score in the 40th percentile, what does that mean?
60 percent of the class scored above you, 40 percent score below.
Who is the 2nd President of the United States of America?
John Adams
Determine whether the number described is a statistic or a parameter.
70% of all voters in a state supported a bill being passed.
Parameter
In the data set, what is the class width?
Number of hours: Frequency:
1-5.9 3
6-10.9 4
11-16.9 8
The class width is 5!
Find the Mean Median and Mode(s) of data set:
0.4, 0.9, 1.3, 1.8, 2.2, 2.7, 3.1, 85.5
Find the Population Standard Deviation of the Data Set:
112,105,117,120
Population Standard Deviation=5.6789083458
What does s mean?
Sample Standard Deviation
Identify the kind of sample that is described.
A salary committee for a Midwestern college uses a random number generator to select
employees based on their employee number and asks them questions about the proposed benefit package.
Simple Random Sample
What is the relative frequency of class "A"?
Number of hours: Frequency:
A: 1-5.9 12
B: 6-10.9 13
C: 11-16.9 10
Relative Frequency is 0.34285714285
In a study of Facebook users conducted in a recent year, the mean number of Facebook friends per user was 298 and the median was 182. If a histogram were constructed for the numbers of Facebook friends for all Facebook users, would you expect it to be skewed to the right, skewed to the left, or approximately symmetric?
The Histogram would be skewed to the right.
Find the Z score of the numbers 26 given the data set:
4.8, 5.1, 5.3, 5.6, 5.9, 72.4, 73.1
The Z-score is 0.0425594174734
Sample mean
Officials at a metropolitan transit authority want to get input from people who use a certain bus route about a possible change in the schedule. On all buses during a certain month, they poll 10 riders on those buses about the change.
What type of Sampling Method was used?
Stratified Sampling was used.
(Image in the PowerPoint) Which way is this skewed?
It is skewed to the right.
In a data set the: Q1=168 , Q2=176,Q3= 235
Find IQR and Upper and Lower Boundary, and find if the number 352 is an outlier
IQR= 67
Lower Boundary=67.5
Upper Boundary=335.5
352 is an outlier
In a large sample of customer accounts, a utility company determined that the average number of days between when a bill was sent out and when the payment was made is 28, with a standard deviation of 5 days. Assume the data to be approximately bell-shaped. (USE EMPIRICAL RULE)
Approximately ____ of the bills have payments made in greater than 38.
2.5%
What is μ?
Population Mean
Determine the 3 factors: Quantitative or Qualitative, Sample Method(s), and Statistic or Parameter. A city has 24 apartment complexes. Researchers randomly select 6 apartment complexes. From each selected complex, every apartment on each floor is surveyed. Researchers then report the percentage of residents who support the plan.
Quantitative, Cluster, and Statistic.
(To the PowerPoint for a sec again) What is the dataset (Leaves are the ones digit)?
1,18,18,23,25,26,27,38
The mean of the data set:
234, 356, 127, 444, x
is 279.2.
Find x
x=235
Find the Z score of the number 286 when the mean is 60, and the standard deviation is 44. If the mean were to increase, would the Z score increase or decrease?
The Z score 5.13636363636
The Z score would decrease.
Find the mean and population Standard Deviation in the data set:
38.141, 37.156, 33.162, 31.179, 39.184, 25.875, 45.24, 41.45
Mean=36.423375
stdevp=5.73929560002