Statistics Solutions

A student chooses 4 books at random from a reading list of 11 books.

Answer: $C(11,4) = 330$ different combinations of books

Sep 1, 2026

11, 14, 22, 19, 23, 22, 22 Find the mean, median, mode, range, variance, and standard deviation.

Answer: Mean = 19 | Median = 22 | Mode = 22 | Range = 12 | Variance

Aug 18, 2026

You are a robotics engineer working for a large tech company. For one of your artificially intelligent robots, you are looking to see if the size of the data file used to train the robot is predictive of the time the robot takes to complete a maze. You are going to collect a random sample of 7 attempts at completing the maze. You will note for each attempt the size of the data file (denoted by x, in MB) and the time (denoted by y, in seconds) to complete the maze. You will also note the product x*y of the size of the data file and the completion time for each attempt. Data file size, x (in MB): 123.8, 99.6, 198.1, 42.5, 61.3, 164.2, 85.4 Completion time, y (in seconds): 134, 253, 85, 386, 423, 157, 226 xy: 16,589.2, 25,198.8, 16,838.5, 16,405, 25,929.9, 25,779.4, 19,300.4 Find: n, x_bar, y_bar, s_x, s_y, sum(xy) Then compute: - Sample correlation coefficient r - Slope b_1 - y-intercept b_0 - Regression equation: y_hat = b_0 + b_1*x

Answer: $n = 7$, $\bar{x} \approx 110.7$ MB, $\bar{y} \approx 237.7$

Jun 18, 2026