In 1990, the mean amount of time car owners kept their cars was 6.6 years and the standard deviation of these times was 3 years. Thinking this mean ownership time may have changed (IN EITHER DIRECTION) over the past decades, a poll of 100 randomly selected car owners was conducted, revealing that the sample mean length of time they plan to keep their car is 7.26 years. We will assume the standard deviation of all times is still 3 years.
What is the population?
[Select]
What is the variable of interest and is this variable Quantitative or Qualitative?
[Select]
In other words: what is the one piece of info we care about for each individual in the population? Is it a quantitative measurement? Or do we determine if each individual belongs to a certain category (referred to as success) or not (failure)?
