f08_1 - Statistics 324 (Bates) Midterm 1 2008-10-09 (p. 1)...

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

View Full Document Right Arrow Icon
Statistics 324 (Bates) Midterm 1 2008-10-09 (p. 1) Choose the most appropriate answer. Mark only one selection. Use pencil. 1. In a single sample of data the 50th percentile is also called the sample (a) mean (b) median (c) range (d) standard deviation (e) variance 2. The formula for the sample standard deviation, s , is (a) p ( n i =1 x i ) /n (b) p ( n i =1 ( x i - ¯ x ) 2 ) /n (c) p ( n i =1 ( x i - ¯ x ) 2 ) / ( n - 1) (d) (∑ n i =1 ( x i - ¯ x ) 2 ) /n (e) (∑ n i =1 ( x i - ¯ x ) 2 ) / ( n - 1). 3. If s is the sample standard deviation and ¯ x is the sample mean we expect about 95% of the data to fall in the interval (a) s ± ¯ x (b) s ± x (c) ¯ x ± s (d) ¯ x ± 2 s (e) ¯ x ± 3 s 4. The box in a box-and-whisker plot covers what portion of the data? (a) 50% (b) 2/3 (c) 95% (d) 99% (e) no specific proportion - it will vary. 5. For a continuous random variable X , which statement is not always true of the probability density function, f ( x )? (a) 0 f ( x ) (b) f ( x ) 1 (c) R -∞ f ( x ) dx = 1 (d) P [ a X b ] = R b a f ( x ) dx (e) P [ a X < b ] = R b a f ( x ) dx 6. Which distribution is most commonly used to model the time to failure of a system? (a) bi- nomial (b) Poisson (c) normal (or Gaussian) (d) uniform (e) exponential 7. Which distribution is a continuous distribution? (a) binomial (b) geometric (c) hypergeomet- ric (d) negative binomial (e) normal (or Gaussian) 8. A binomial random variable, X , models the total number of successes in n independent, identical trials, each with probability
Background image of page 1

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

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/06/2010 for the course STATS 324 taught by Professor Bates during the Fall '08 term at Wisconsin.

Page1 / 3

f08_1 - Statistics 324 (Bates) Midterm 1 2008-10-09 (p. 1)...

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

View Full Document Right Arrow Icon
Ask a homework question - tutors are online