Week 1 stats

• What is the main focus of statistics as a science?

  Statistics is about collecting, organizing, summarizing, analyzing, and interpreting data.
• Why is data expertise increasingly important according to the Royal Society report?

  About 10% of job adverts required data expertise, indicating growing demand.
• What are the two main branches of statistics?

  Descriptive statistics and inferential statistics.
• What is the purpose of descriptive statistics?

  Descriptive statistics is about organizing, summarizing, and describing data.
• How does inferential statistics differ from descriptive statistics?

  Inferential statistics uses sample data to draw conclusions about a larger population.
• What is a population in statistics?

  A population is a large set that is the target of interest.
• What is a sample in statistics?

  A sample is a subset of the target population.
• What is an experimental unit?

  An experimental unit is an object upon which measurements or observations are collected.
• What is a variable in statistics?

  A variable is a characteristic property of an individual experimental unit.
• If we are interested in the weights of students at University of West London, what would be our variable?

  The variable would be the weights of the students.
• What are the two types of data in statistics?

  Quantitative and qualitative data.
• What is quantitative data?

  Quantitative data is numerical data that can be discrete or continuous.
• What is qualitative data?

  Qualitative data is non-numerical or categorical data.
• What is a statistic?

  A statistic describes a characteristic of a sample.
• What distinguishes nominal data from ordinal data?

  Nominal data cannot be sensibly ranked, while ordinal data can be ranked.
• What is a parameter?

  A parameter describes a characteristic of a population.
• What are the three measures of central tendency?

  The three measures are mean, median, and mode.
• What is the formula for the sample mean?

  The sample mean is .
• What is the formula for the population mean?

  The population mean is .
• What is the mean of the following exam scores: 11, 43, 55, 62, 57, 5, 95, 52, 70, 93?

  The mean is .
• Why can the mean be misleading in certain data distributions?

  The mean can be misleading if the data is highly skewed.
• What is the median?

  The median is the value that splits the data set into two halves.
• How is the sample median calculated for an odd number of observations?

  The sample median is .
• How is the sample median calculated for an even number of observations?

  The sample median is .
• What is the median of the exam scores: 5, 11, 43, 52, 55, 57, 62, 70, 93, 95?

  The median is .
• What is the mode?

  The mode is the value that occurs with the greatest frequency.
• What does it mean if a data set is bimodal?

  A bimodal data set has two modes, or values that occur with the greatest frequency.
• Why are measures of dispersion important?

  Measures of dispersion help differentiate between data sets that have the same central tendency.
• What is the formula for the range?

  The range is .
• What is the range of the ages of the 27 students if the minimum age is 18 and the maximum age is 70?

  The range is .
• What is the formula for sample variance?

  The sample variance is .
• What is the formula for population variance?

  The population variance is .
• What is the formula for sample standard deviation?

  The sample standard deviation is .
• What is the formula for population standard deviation?

  The population standard deviation is .
• What is a rough measure of spread in a data set?

  Range
• How is the range of a data set calculated?

  The range is calculated as .
• Given the ages of 27 students with a minimum age of 18 and a maximum age of 70, what is the range?

  The range is .
• What are the most popular measures of spread?

  Variance and standard deviation
• How is the sample variance calculated?

  The sample variance is calculated as .
• How is the sample standard deviation derived from the sample variance?

  The sample standard deviation is .