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Unformatted text preview: STA 2023 Sample Exam I Name: INSTRUCTIONS 1. Fill in all the spaces above with the required information. 2. Make sure your exam has 5 pages with 8 problems. The student is responsible for making sure the exam is nondefective. 3. This exam is worth a total of 100 points. The point value of each question is indicated in parentheses. 4. If a problem says SET UP , put all numbers into the appropriate formula(s), leaving no symbols or letters. You need not go through the arithmetic computations to arrive at the final numerical answer. 5. For questions that are to be worked out, show your work in the space provided . No partial credit can be given unless you show your work. Full credit will be given only if correct reasoning is included. 6. When turning in the exam, show your picture i.d. FORMULAS x = ∑ x n s 2 = ∑ ( x- x ) 2 n- 1 = ∑ x 2- ( ∑ x ) 2 n n- 1 P( A ) = 1- P( A c ) P( A | B ) = P( A ∩ B ) P( B ) P( A ∪ B ) = P( A ) + P( B )- P( A ∩ B ) P( A ∩ B ) = P( A )P( B | A ) = P( B )P( A | B ) A = ( A ∩ B ) ∪ ( A ∩ B c ) P( A ) = P( A ∩ B )+P( A ∩ B c ) μ = E ( x ) = X xp ( x ) σ 2 = E h ( X- μ ) 2 i = X ( x- μ ) 2 p ( x ) = E ( x 2 )- μ 2 = X x 2 p ( x )- μ 2 For a binomial random variable: μ = np σ 2 = npq p ( x ) = n x ! p x q n- x where n x ! = n ! x !( n- x )! STA 2023 Intro to Stat I Sample Exam I 1 1. A buyer for a lumber company must decide whether to buy a piece of land on which 5000 trees are growing. If 1000 of the trees are at least 60 feet tall, the buyer will purchase the land; otherwise, he will not. The owner of the land reports that the height of trees has mean 50 feet and standard deviation 3 feet....
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- Fall '08
- Statistics, Probability theory, pts, voter registration