📊 statistics

1. **Problem Statement:** James has calculated the mean and median of a data set. The median is 147.5 and the mean is 209.6. We need to determine if the difference between these tw

1. **Problem Statement:** We have a sample of 16 ten-year-old girls with a mean weight $\bar{x} = 71.5$ pounds and a standard deviation $s = 12$ pounds. We want to find the 90%, 95

1. **Problem Statement:** Find the reliability factor (critical t-value) from the t-distribution for given confidence coefficients and sample sizes. 2. **Formula and Explanation:**

1. The problem presents three matrices A, B, and C with numeric values arranged in 10 rows and 5 columns each. 2. Since no specific question is asked, we can analyze or summarize t

1. **State the problem:** We want to test if the average effect level of change in foreign exchange rates is greater than 0.4 using the given sample data and a 5% significance leve

1. **Problem Statement:** Given data points $x = \{1, 2, 3, 4\}$ and $y = \{2, 3, 7, 8\}$, we need to find means, standard deviations, regression lines, correlation coefficient, an

1. The problem appears to be a list of numbers: 20, 12, 3, 8, 12, 9. 2. Since no specific question is asked, let's analyze these numbers for common algebraic or arithmetic properti

1. Problem 1: Frequency distribution of heights of 50 students. 1. a. Find the lower limit of the median class.

1. **State the problem:** We want to find the average annual increase in world population between 1990 and 2010, given population data points for 1990, 2000, and 2010. 2. **Given d

1. **State the problem:** We are given a set of test scores and need to create a frequency distribution table with intervals 66-71, 72-77, 78-83, and 84-89. 2. **List the test scor

1. The problem involves interpreting a dot plot that shows the number of students reporting the number of letters in their last names. 2. The horizontal axis is labeled "Number of

1. **State the problem:** We are given a linear regression equation $\hat{y} = 3.27 + 0.56x$ where $x$ is the stride length (m) and $\hat{y}$ is the predicted speed (m/s). We want

1. The problem asks to identify which scatter diagrams correspond to specific types of linear correlations between variables $x$ and $y$. 2. Important concepts:

1. The problem asks to identify which scatter diagrams correspond to the strongest positive and negative linear correlations between variables $x$ and $y$. 2. Recall that a positiv

1. **State the problem:** We have 10 calorie values from mid-sized hamburgers: 515, 507, 501, 497, 495, 507, 458, 477, 463, 513. We need to find the mean and the sample standard de

1. The first problem involves understanding the mean and sample standard deviation of calories in a mid-sized hamburger. 2. The mean is given as $493.30$, which represents the aver

1. **Problem 1: Robocalls Data Analysis** We have 12 data points representing robocalls: 77, 80, 84, 87, 83, 94, 82, 82, 76, 78, 74, 81.

1. **State the problem:** We have data of wave length (independent variable $x$) and speed (dependent variable $y$). We want to find the linear regression line $\hat{y} = b_0 + b_1

1. **Problem Statement:** We have odometer readings (independent variable $x$) and retail values (dependent variable $y$). We want to find the least-squares regression line, predic

1. **Problem 29:** Find the t-value for df = 11 where the area to the left is 0.025. - This corresponds to the lower 2.5% tail of the t-distribution with 11 degrees of freedom.

1. **Stating the problem:** We are given the definitions of covariance $\sigma(X,Y)$ and correlation coefficient $\rho_{X,Y}$ between two random variables $X$ and $Y$: