use the Gauss-Jordan method to find the inverse of the given matrix (if it exists). Partitioning large square matrices can sometimes make theirinverses easier to compute, particularly if the blocks havea nice form. In Exercises 6468, verify by block multiplicationthat the inverse of a matrix, if partitioned as shown, isas claimed. (Assume that all inverses exist as needed.)

MAT 221 – Chapter 2 Looking at Data - Relationships 2.1 & 2.2: Relationships & Scatterplots Scatterplot- one axis is used to represent each of the variables and the data are plotted as points on the graph Three Aspects of a Relationship: 1. Direction- positive or negative a. Positive: greater values of one variable tend to occur w/ greater values of other values (ex. House size and price) b. Negative: greater values of one variable tend to occur w/ smaller values of other variable (ex. Weight of cars and fuel efficiency) 2. Form – linear, curved, clusters, no pattern 3. Strength – how closely the points fit the form No relationship- the variables are independent Explanatory (independent) variable – the one that controls the other variable [x-axis] Response (dependent) variable – the one that moves based on the other variable [y-axis] Outlier- anything that doesn’t follow the trend 2.3 Correlation Correlation (coefficient) r – a numerical measure of the direction and strength of the relationship between 2 quantitative variables Properties: - Value r ranges from -1 to 1 - Gives the direction of the relationship - Closer to 1 or -1 is a strong relationship - Closer to 0 is a weak relationship - Very sensitive to outliers How to calculate: - For each case in the sample we have a pair of values (x,y) - Suppose there are n cases (x1,y1), (x2,y2),