Answer to Question #127290 in Statistics and Probability for eyob tilahun

Question

give short answer
for questions 1-3 indicate as discrete and continuous variable
1. number of students in a class.........
2. weight and IQ score...............
3.number of book in library..........
4. write down the properties of point estimators
5. calculate the interval (with 90% level) containing the population mean of performance based on the information given. given: σ=18;n=36 x̄=85

Answer 1

1. number of students in a class - Discrete

2. weight and IQ score - Continuous

3.number of book in library - Discrete

4.The bias of a point estimator is defined as the difference between the expected value of the estimator and the value of the parameter being estimated. Consistency tells us how close the point estimator stays to the value of the parameter as it increases in size. The most efficient point estimator is the one with the smallest variance of all the unbiased and consistent estimators. The variance measures the level of dispersion from the estimate, and the smallest variance should vary the least from one sample to the other.

5. interval = X ± Z*σ/$\sqrt n$

z=1.645 (for 90% confidence)

90% Confidence Interval: 85 ± 4.93 (80.1 to 89.9)