01 & 02 STAT HWA a

# 01 & 02 STAT HWA a - Dr Valerie R Bencivenga Economics...

This preview shows pages 1–2. Sign up to view the full content.

Dr. Valerie R. Bencivenga Economics 329 PRACTICE HOMEWORK #1A: ANSWERS 1.a. discrete b. continuous c. discrete (dummy) d. discrete e. continuous (or approximately continuous) 2.a. Mode . It does not make sense to average nuclear power plants and hydroelectric plants. b. Median . This variable probably has a skewed distribution, with a small number of households having large net worth. The mean would be distorted by this small number of large values of the variable. c. Mean . There is no reason to think that this variable has a skewed distribution. d. Mean . There is no reason to think that this variable has a skewed distribution. But if, upon examining the data, it seems that a small number of workers work lots of overtime, and that this will distort the mean, then the median would be preferred. e. Median . This variable probably has a very skewed distribution, where a small number of very valuable homes would distort the mean. 3.a. millions of hours per year, or just millions of hours. b. 1/year or “per year” if the growth rate is stated as a proportional growth rate, and %/year or “percent per year” if the growth rate is stated in percentage points (or just unit -free). c. (millions of hours per year) 2 , or (millions of hours) 2 . d. millions of hour per year times billions of dollars per year, or just millions of hours times billions of dollars. e. unit-free. 4.a. The mean will increase, because a positive value is being added to the original set of deviations. b. The variance will increase. The variance is n 1 i 2 i 2 X ) X X ( 1 n 1 s . Obviously, if we add an observation whose value equals X , the variance declines, because the sum of squared deviations does not increase, and the denominator increases. However, the addition of a value above X will increase the mean and add a term to the sum and increase the denominator. Intuitively, if we add an observation to the upper part of the distribution of the variable

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 4

01 & 02 STAT HWA a - Dr Valerie R Bencivenga Economics...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online