- CFA Exams
- CFA Level I Exam
- Topic 1. Quantitative Methods
- Learning Module 7. Estimation and Inference
- Subject 1. Sampling Methods
CFA Practice Question
Mileage tests were conducted on a randomly selected sample of 100 newly developed automobile tires. The average tread wear was found to be 50,000 miles with a standard deviation of 3,500 miles. What is the best estimate of the average tread life, in miles, for the entire population of these tires?
B. (3,500/100)
C. (50,000/100)
A. 50,000
B. (3,500/100)
C. (50,000/100)
Correct Answer: A
The sample mean is a good estimate of the population mean.
User Contributed Comments 5
| User | Comment |
|---|---|
| 8thlegend | I spent 10 mins figuring out how to do this. Then i realized that this was the first question and wasted 10 mins of my life. |
| thekid | 8thlegend---> 10minutes + the time it took you to post up your comment in regards to this "first question" lol..i'm going insane. |
| Ktrain | 10 minutes + the 250 hours studying for this test |
| 2014 | Sample represents population, The purpose of picking up sample serves the estimation of same results. U cannot do research on entire population of tyres. So u have selected a sample. Now, sample results u would rely to predict information. There is no choice or this is best choice to estimate |
| JMORALES | haha |