How do I know if two ratios are equivalent

Use this data in the problem below. follow the steps carefully. round to the nearest tenth. lot 3: week 1: 345 week 2: 340 week 3: 400 week 4: 325 step 1. jim enters the data and calculates the average or mean. step 2. jim calculates the deviation from the mean by subtracting the mean from each value. step 3. jim squares each deviation to remove negative signs. step 4. jim sums the squares of each deviation and divides by the count for the variance. step 5. jim takes the square root of the variance to find the standard deviation.

How do the definitions, properties, and postulates you've learned about line segments, parallel lines, and angles to define the shapes of polygons

The roots of the function f(x) = x2 – 2x – 3 are shown. what is the missing number?