1. Alexa, Becky, Charlene, Daniella, and Eileen are 11,12,12,13 and 14 years old, respectively. What are the mean, median, mode, variance, and standard deviation of their ages? Use the table below to help show your work.
|
|
Xi
|
Xi-x-(X')
|
|
(X')2
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Sum
|
|
|
Sum
|
|
|
n
|
|
|
Variance
|
|
|
Mean
|
|
|
Standard Deviation
|
|
2. What data type (nominal, ordinal, interval, or ratio) are the following variables:
|
Variable
|
Scale
|
Data Type
|
|
How many hours of sleep do you get per night?
|
1- Less than 4 hours
2- Between 4 and 6 hours
3- More than 6 hours
|
|
|
Ethnicity
|
1- Hispanic/Latino
2- Caucasian
3- African American
|
|
|
Income
|
Salary Value
|
|
|
What grade are you in?
|
Number Grade 1 to 12
|
|
3. Use the normal distribution below to answer the following questions.
What is the mean number of hours of sleep that people get each night?
What is the standard deviation of the variable "hours of sleep per night"?
What is the variance of the variable "hours of sleep per night"?
What is the range of hours of sleep the middle 95% of people get each night?
