BSTAT 2305 – 005
EXAM #1
Name: __________________
Date: __________________
UTA Email: __________________
Instructions:
You have been provided exam paper to answer the questions on. Please fill out answers in
scantron, making sure to include your name, date, and UTA’s email on this paper and scantron.
Please only supply information related to the question. Please do not leave anything behind in the
classroom. When you are finished turning in the exam, please quietly exit the classroom and
have an amazing rest of the day! Best of luck!
The following may be of use to you to solve questions.
Arithmetic mean: 𝜇 =
∑𝑁
𝑖=1 𝑥𝑖
𝑁
∑𝑛
𝑖=1 𝑥𝑖
, 𝑥̅ =
𝑛
Weighted mean for sample: 𝑥̅ = ∑𝑛𝑖=1(𝑤𝑖 ) × (𝑥𝑖 ) 𝑓𝑜𝑟 𝑖 = 1, 2, … , 𝑛
Mean absolute deviation (MAD): Population MAD =
Variance: 𝜎 2 =
2
∑𝑁
𝑖=1(𝑥𝑖 −𝜇)
𝑁
, 𝑠2 =
∑𝑁
𝑖=1 |𝑥𝑖 −𝜇|
𝑁
, Sample MAD =
𝑛−1
𝜎
s
𝜇
𝑥̅
∑𝑁
𝑖=1(𝑥𝑖 −𝜇𝑥 )×(𝑦𝑖 −𝜇𝑦 )
∑𝑛
̅)
𝑖=1(𝑥𝑖 −𝑥̅ )×(𝑦𝑖 −𝑦
𝑁
𝑛−1
Correlation coefficient: 𝜌𝑥𝑦 =
𝑛
2
∑𝑛
𝑖=1(𝑥𝑖 −𝑥̅ )
Coefficient of variation (CV): Population CV = , Sample CV =
Covariance: 𝜎𝑥𝑦 =
∑𝑛
𝑖=1 |𝑥𝑖 −𝑥̅ |
, 𝑠𝑥𝑦 =
𝜎𝑥𝑦
𝜎𝑥 ×𝜎𝑦
, 𝑟𝑥𝑦 =
𝑠𝑥𝑦
𝑠𝑥 ×𝑠𝑦
Addition rule: P(A ∪ B) = P(A) + P(B) − P(A ∩ B), Complement rule: P(𝐴𝑐 ) = 1 − P(A)
Multiplication rule: P(A ∩ B) = P(A|B) × P(B) = P(B|A) × P(A)