Biostatistics — Winter 2025

Explain binomial distribution with the formula and example when its used.

Describe how a histogram and a pie chart are used to display frequency distributions. State one limitation of each in biological data analysis

Abiotechnology company is testing whether three different storage temperatures impact the shelf life (in days) of a probiotic supplement. Supplement samples are randomly divided into three groups and stored at 4°C, 20°C, and 37°C. After a standardized period, the shelf life for each sample is recorded in whole days. The company wants to know if there is a significant difference in the mean shelf life between the temperature groups, using one-way ANOVA. F-value for , at is 3.55. Temperature Shelf Life (days) 4°C 29, 32, 34, 30, 28, 36, 27 20°C 19, 24, 21, 26, 25, 18, 22 37°C 14, 11, 16, 12, 15, 10, 13

What is kurtosis and why is it significant in statistical data?

Define skewness. Explain types with relevant examples. Page 1 of

Abiotechnology researcher wants to study whether there is a relationship between the seedling height (in cm) and root length (in cm) of 8 genetically modified plant samples. She suspects that seedlings with greater height may also develop longer roots but is not sure if the relationship is strong or even monotonic. Calculate the Spearman's rank correlation coefficient to determine the strength and direction of the association between height and root length. Root Plant Height Length Sample(cm) (cm)

Aresearcher studying plant growth wants to understand the relationship between the number of irrigation cycles (X) and the observed stem length (Y) in a greenhouse experiment. The researcher collects the following pairs of observations on Xand Y: Stem Irrigation length cycles (Y, (X) cm)12 1. Find the two regression equations (of Yon Xand Xon Y) from these pairs. 2. Hence, calculate:

The predicted value of stem length Ywhen X = 2.5 irrigation cycles and ii) The predicted value of irrigation cycles Xwhen stem length Y = 4.5 cm

State difference between Histogram and frequency polygon for graphical representation of statistical data.

Define non-parametric tests. Explain why the Mann-Whitney Utest would be preferred over the t-test in comparing two small independent groups. Page 2 of

Applications of fertilizers were tested for the yield of rice grown in 10 plots. Another seed of 10 plots of similar size & condition were taken as control. Test the effect of fertilizer. (Reference value at significance level 5% = 2.10)

Give difference between graph and diagram.

Compare parametric and non-parametric tests focusing on assumptions, types of data, and examples of each test.

During an experiment to evaluate dietary effects on rat body weight, ten rats were weighed after being fed rice for one month. Subsequently, the rats were provided grams in their diet for another month, and their weights were measured again. The table below presents the body weights (in grams) of each rat for both periods. Use the data to investigate whether replacing rice with grams in the rats' nutrition resulted in a statistically significant change in their body weights. (Reference table value at 5% significance level, with DoF=9 are Two-tailed= 2.26; One-tailed= 1.83) Rat1 Rat2 Rat3 Rat4 Rat5 Rat6 Rat7 Rat8 Rat9 Rat10 Weight Month Weight Month

In a class of 50 biotechnology students: 30 students study Bioinformatics 25 students study Molecular Biology 15 students study both Bioinformatics and Molecular Biology Draw a Venn diagram to represent this information. Also, find:

The number of students who study only Bioinformatics

The number of students who study only Molecular Biology

The number of students who study neither subject

Abag contains 5 white and 3 black balls. Two balls are drawn at random one after the other without replacement. Find the probability that both the balls drawn are black.

Acollege conducts both day & night classes intended to be identical. Asample of 100 day students yields examination results as under. X1 = 72.4 & σ1 = 14.8. Asample of 200 night students yields examination results as under X2 = 73.9 & σ2 = 17.9. Are the two means statistically equal at 10% level? (Table value: Z = 1.645)

Define: Deciles and Z – score, write the brief about their calculation

Calculate the arithmetic mean for the daily wages from the following data:

Calculate the mean, median, S.D. variance and covariance of the following data:

Define: Percentiles, Quartiles, Quintiles

Find the median & median class of the data given below:

Work out the mean & the standard error of the mean of the following frequency distribution of blood sugar scores (mg per deciliter) of a sample of goats. Page 4 of