Lectures 11-14: Biostatistics

Question 1

What is one key purpose of using statistics in research?

Answer 1

To determine the prevalence of diseases, identify risk factors, and assess the effectiveness of treatments.

Question 2

Why is it important to compare study findings with expected results?

Answer 2

To validate hypotheses and ensure the reliability and accuracy of the study conclusions.

Question 3

How can you compare the findings of a study with expected results?

Answer 3

By using statistical tests to determine if there are significant differences between the observed data and the expected results.

Question 4

What is a confidence interval?

Answer 4

A confidence interval is a range of values, derived from a sample, that is likely to contain the population parameter.

Question 5

What is the generic formula for calculating a confidence interval?

Answer 5

The generic formula is:
SampleMean±(CriticalValue×StandardError).

Question 6

What is a correct interpretation of a 95% confidence interval?

Answer 6

A correct interpretation is that we are 95% confident that the true population parameter lies within the interval.

Question 7

What is an incorrect interpretation of a 95% confidence interval?

Answer 7

An incorrect interpretation is that there is a 95% probability that the population parameter lies within the interval.

Question 8

When could bias influence sampling?

Answer 8

Bias could influence sampling when the selection process is not random or when certain groups are overrepresented or underrepresented.

Question 9

How can you recognize a normal curve?

Answer 9

A normal curve is a symmetric, bell-shaped curve centered around the mean.

Question 10

When is a sampling distribution expected to follow a normal bell-shaped curve?

Answer 10

A sampling distribution follows a normal bell-shaped curve when the sample size is large enough, typically due to the Central Limit Theorem.

Question 11

How does the spread of the sampling distribution change with sample size?

Answer 11

The spread of the sampling distribution decreases as the sample size increases.

Question 12

What describes the sampling distribution for comparing two groups?

Answer 12

The sampling distribution for comparing two groups is centered on the difference between their population means and its spread is determined by the standard errors of the two samples.

Question 13

What are the key characteristics used to describe the distributions of population, sample, and sampling distribution?

Answer 13

Population is described by mean and standard deviation, sample by sample mean and sample standard deviation, and sampling distribution by the population mean (if unbiased) and standard error.

Question 14

What is the standard error?

Answer 14

The standard error is the standard deviation of the sampling distribution.

Question 15

What information is needed to draw the shape of a normal distribution?

Answer 15

The mean and standard deviation are needed to draw the shape of a normal distribution.

Question 16

What is the equation of a regression line?

Answer 16

The equation of a regression line is y = a + b × x, where a is the intercept, b is the slope, and x is the variable.

Question 17

What is the general process of sampling?

Answer 17

Sampling involves selecting a subset of individuals from a population to represent the whole population.

Question 18

What is the difference between a population and a sample?

Answer 18

A population includes all individuals of interest, while a sample is a subset of the population used for study.

Question 19

Why do we take samples in statistics?

Answer 19

Samples are taken to make inferences about the entire population without having to study everyone.

Question 20

What is the difference between location (central tendency) and spread in statistics?

Answer 20

Location (central tendency) measures where the data centers (e.g., mean, median), while spread measures the variability or dispersion of the data (e.g., range, standard deviation).

Question 21

Why are statistics important in health sciences?

Answer 21

Statistics help understand the health of the population, including the prevalence of diseases, risk factors, and the effectiveness of treatments.

Question 22

How is the mean calculated?

Answer 22

The mean is calculated by dividing the sum of all values by the total number of observations.