Biostatistics — Flashcards

Flashcard 91: observed Hb=18 g/dl mean Hb=14 g/dl standard deviation =2 g/dl z score=?

Answer: z score=2

Extra: 

Flashcard 92: For small samples, to calculate significance of difference between means, t-test is applied →To compare unpaired data i.e independent observations done on individuals of two different or separate groups or samples drawn from two populations, _____ is used → t-value can be calculated by, \(t=\) _____, where s = _____

Answer: unpaired t-test

Extra:  y

Flashcard 93: What is the formula for calculating sensitivity? _____

Answer: Sensitivity = TP / (TP + FN)

Flashcard 94: Formula for Mean for grouped data (where values are categorized): \(X_g\) = mid-point of each group \(f\) = frequency of each group Mean (\(\bar X\)) = _____

Answer: \(\frac{\sum (f \cdot X_g)}{n}\)

Flashcard 95: _____ was the founder of demography

Answer: Achille guillard

Extra: 

Flashcard 96: Some other measures of variability are: →Range = _____ →Coefficient of Range = _____ →Quartile Deviation = _____ →Coefficient of Quartile Deviation = _____ where, \(H\ =\ Highest\ Value\) \(L\ =\ Lowest\ Value\) \(Q_3 = 3(\frac {n+1}{4})^{th} observation\) \(Q_1 = (\frac {n+1}{4})^{th} observation\)

Answer: \(H-L\) 

Extra: y

Flashcard 97: c65872b736324b578b20a22eef5c027a-ao-6

Answer: tests of significance

Extra: 

Flashcard 98: geometric mean is calculated in cases of _____

Answer: extreme values and exponential data

Extra: 

Flashcard 99: Formula for Negative Predictive Value (NPV)

Answer: NPV = True Negatives / (True Negatives + False Negatives) Alternatively: d / (c + d)

Extra: Negative Predictive Value (NPV) is the probability that a person with a negative test result is truly free of the disease.

Flashcard 100: Coefficient of variation (CV) is given by: _____

Answer: \(\frac{SD}{Mean} \times 100\%\)

Extra: The coefficient of variation (CV) is a statistical measure of the relative dispersion of data points in a data series around the mean. It is expressed as a percentage.