Question 1: Define the term 'mean' in the context of descriptive statistics.

Answer: The mean is the average value of a set of data, calculated by adding all the numbers together and dividing by the total number of values.

Question 2: A class of 30 students took a psychology test. Their scores ranged from 45 to 85. The scores are: 45, 50, 55, 60, 65, 70, 75, 80, 85. Calculate the range of the scores.

Answer: Range = Highest score - Lowest score = 85 - 45 = 40

Question 3: Explain what the median score represents in a data set.

Answer: The median is the middle value when all the data points are arranged in order; it separates the lower half from the upper half of the data.

Question 4: Given the scores 55, 60, 65, 70, 75, 80, 85, identify the mode of this data set.

Answer: There is no mode because all scores occur only once.

Question 5: A teacher records the number of questions students get correct in a quiz: 8, 9, 7, 10, 9, 8, 7. Calculate the mean score.

Answer: Sum of scores = 8 + 9 + 7 + 10 + 9 + 8 + 7 = 58. Number of scores = 7. Mean = 58 ÷ 7 ≈ 8.29

Question 6: Describe how you would find the mode in a set of data.

Answer: Identify the value that appears most frequently in the data set.

Question 7: A data set of reaction times in seconds is: 1.2, 1.4, 1.3, 1.2, 1.5, 1.2. Draw a simple bar chart to represent the frequency of each reaction time.

Answer: A bar chart with reaction times on the x-axis (1.2, 1.3, 1.4, 1.5) and frequency on the y-axis; bars for 1.2 (3 times), 1.3 (1), 1.4 (1), 1.5 (1).

Question 8: Sketch a box plot for the following data: 12, 15, 14, 16, 18, 20, 22.

Answer: A box plot showing the minimum (12), lower quartile (~14), median (16), upper quartile (~20), and maximum (22), with a box spanning from Q1 to Q3, and lines (whiskers) extending to the min and max.

Question 9: Explain why the mean can be affected by extremely high or low scores in a data set.

Answer: Because the mean takes all values into account, extremely high or low scores can skew the average, making it not representative of the overall data.

Question 10: A researcher records the following number of hours students sleep: 6, 7, 8, 5, 9, 7, 8. Calculate the median number of hours slept.

Answer: Arrange data in order: 5, 6, 7, 7, 8, 8, 9. The median is the middle value: 7 hours.