1. Which of the following is NOT a basic assumption of normal distribution in plant biometry?
a) The data is symmetrically distributed around the mean
b) The distribution has a bell-shaped curve
c) Data points are clustered around the median
d) The variance of the data is constant across the range of values
Answer: c) Data points are clustered around the median
Explanation: In a normal distribution, data points are clustered around the mean, not the median. The mean, median, and mode are all the same in a perfectly normal distribution.
2. In plant biometry, which of the following statistical methods is used to estimate the variability of a sample relative to its mean?
a) Standard deviation
b) Correlation coefficient
c) Mode
d) Median
Answer: a) Standard deviation
Explanation: The standard deviation is used to measure the spread or dispersion of a set of values in relation to the mean. It quantifies the degree of variation or consistency in the data.
3. Which of the following is the best method to test whether a given dataset follows a normal distribution?
a) T-test
b) Chi-square test
c) Shapiro-Wilk test
d) ANOVA
Answer: c) Shapiro-Wilk test
Explanation: The Shapiro-Wilk test is a statistical test specifically designed to assess the normality of a dataset. It is commonly used to test if data follows a normal distribution.
4. The coefficient of variation (CV) is used to:
a) Measure the central tendency of a dataset
b) Compare the variability of data between different datasets
c) Calculate the correlation between two variables
d) Identify the mode of a dataset
Answer: b) Compare the variability of data between different datasets
Explanation: The coefficient of variation (CV) is the ratio of the standard deviation to the mean and is used to compare the relative variability between datasets with different units or scales.
5. Which of the following methods is used for determining the degree of association between two variables in plant biometry?
a) Regression analysis
b) T-test
c) Factor analysis
d) Chi-square test
Answer: a) Regression analysis
Explanation: Regression analysis is used to examine the relationship between two or more variables, and how one variable affects the other, making it a suitable method for determining the degree of association.
6. In a dataset, if the mean is 20, the median is 18, and the mode is 15, the distribution is likely to be:
a) Symmetrical
b) Skewed to the left
c) Skewed to the right
d) Uniform
Answer: b) Skewed to the left
Explanation: If the mean is greater than the median, and the median is greater than the mode, the distribution is skewed to the left (negatively skewed).
7. In the context of plant biometry, which of the following is true about the standard error of the mean (SEM)?
a) SEM is always larger than the standard deviation
b) SEM is used to estimate the precision of the sample mean
c) SEM is the same as the standard deviation
d) SEM is used to test the hypothesis of the dataset
Answer: b) SEM is used to estimate the precision of the sample mean
Explanation: The standard error of the mean (SEM) is used to estimate how accurately the sample mean represents the population mean. It is the standard deviation divided by the square root of the sample size.
8. Which of the following is used to analyze the relationship between a dependent variable and multiple independent variables in plant biometry?
a) Simple linear regression
b) Multiple linear regression
c) Pearson’s correlation
d) Chi-square test
Answer: b) Multiple linear regression
Explanation: Multiple linear regression is used to model the relationship between one dependent variable and two or more independent variables, helping to understand the impact of multiple factors simultaneously.
9. In biometry, when sampling a plant population, which of the following factors is most important for determining the sample size?
a) The variability of the population
b) The desired confidence level
c) The margin of error
d) All of the above
Answer: d) All of the above
Explanation: The sample size is influenced by the variability within the population, the desired confidence level (usually 95% or 99%), and the margin of error (the degree of precision required in the estimate).
10. Which of the following is an appropriate graphical representation for showing the frequency distribution of plant height data?
a) Pie chart
b) Histogram
c) Scatter plot
d) Box plot
Answer: b) Histogram
Explanation: A histogram is ideal for displaying the frequency distribution of a continuous variable like plant height. It visually shows the distribution of data by grouping values into bins.
11. Which of the following is a measure of the symmetry of a distribution in plant biometry?
a) Mean
b) Skewness
c) Kurtosis
d) Variance
Answer: b) Skewness
Explanation: Skewness measures the asymmetry or skew of the data distribution. A skewness of zero indicates a perfectly symmetrical distribution, while positive or negative skew indicates skewed data.
12. The purpose of using a control group in a plant experiment is to:
a) Increase the sample size
b) Establish a baseline for comparison
c) Test the hypothesis
d) Increase the statistical significance
Answer: b) Establish a baseline for comparison
Explanation: A control group is used in experiments to serve as a baseline, allowing researchers to compare the effect of the treatment or intervention against the natural or untreated condition.
13. If the correlation coefficient between two variables is 0.85, what does this indicate?
a) There is no correlation between the variables
b) There is a strong positive linear relationship between the variables
c) There is a strong negative linear relationship between the variables
d) The variables are perfectly correlated
Answer: b) There is a strong positive linear relationship between the variables
Explanation: A correlation coefficient of 0.85 indicates a strong positive relationship, where as one variable increases, the other tends to increase as well.
14. Which of the following tests is used to determine whether the means of two groups are statistically different in plant biometry?
a) Chi-square test
b) T-test
c) ANOVA
d) Regression analysis
Answer: b) T-test
Explanation: A t-test is used to determine if there is a significant difference between the means of two groups. It is commonly applied in plant biometry to compare different treatments or conditions.
15. What does a p-value of 0.03 in a hypothesis test indicate?
a) There is a 97% chance that the null hypothesis is true
b) The result is statistically significant at the 5% significance level
c) The alternative hypothesis is incorrect
d) The null hypothesis should not be rejected
Answer: b) The result is statistically significant at the 5% significance level
Explanation: A p-value of 0.03 means that there is a 3% probability that the observed results occurred by chance, and since it is less than the typical significance level of 0.05, the result is considered statistically significant.