Biostatistics — Flashcards

Flashcard 121: For applying Z-test, \(Z = \) _____ Now to test significance, _____ or, \(Z=\) _____, where s = _____ If _____ at given level of significance, then the observed difference is said to be statistically _____ (_____ is rejected in favor of _____)

Answer: \(\frac {Observed \ difference \ between \ two \ sample \ means}{SE \ of \ difference \ between \ two \ sample \ means}\)

Extra:  y

Flashcard 122: For small samples, to calculate significance of difference between means, t-test is applied, → To compare paired data i.e. independent observations from one sample only, _____ is used t-value is given by, \(t=\) _____

Answer: paired t-test

Extra:  y

Flashcard 123: formula for false negative error rate(FNER)

Answer: Fn/Fn+Tp

Extra: 

Flashcard 124: false negative error rate is related to _____ error

Answer: type 2

Extra: 

Flashcard 125: Major determinant of age dependency ratio is _____

Answer: young dependency ratio

Flashcard 126: Variance =

Answer: (SD)²

Flashcard 127: First synchronous census in India was conducted in _____

Answer: 1881

Extra: The first census in India was conducted in 1872 (non-synchronous). Since 1881, synchronous censuses have been conducted every 10 years.

Flashcard 128: Formula for Mean for grouped data using the assumed mean method, where, → \(Xg = Mid-point \ of \ each \ groups \ is \ taken \) and, any convenient group may be taken as working mean (\(w\)) → \(f = frequency \ of \ each \ group\) → Working units are denoted as, _____ where, \(i = Group \ interval\) → Then, Grouped weight is derived by \(f \times X \) Now, Mean in Working units is, _____ Real Mean is given by, _____

Answer: \(X = \frac {Xg - w}{i}\)

Extra: y

Flashcard 129: Formula for False Positive Error Rate (FPER)

Answer: b / (b + d) (or 1 - Specificity)

Extra: False Positive Error Rate (FPER) is the proportion of healthy individuals (those without the disease) who are incorrectly identified as having the disease by a screening test. It is equivalent to 1 - Specificity.

Flashcard 130: For small samples, to calculate significance of difference between means, t-test is applied → To compare the mean of a single group of observations with a specified value, _____ is done → \(t = \) _____ → Obtained value is compared to t-value given for given degree of freedom (_____) and significance level (corresponding p-value) from table → If t-value obtained > given t-value, then the difference is said to be statistically _____

Answer: One sample t-test

Extra:  y