Question

Fire disturbance of terrestrial biomes is one of the primary factors in non-native plant species growth. A 2014 study by Pec and Carlton investigated the aftereffects of controlled fires on non-native grass growth. The data provided give measurements of the biomass in milligrams of non-native grass and native chaparral shrubs for several randomly selected plots of land in Bell Canyon, California. Click to download the data in your preferred format. CrunchIt! CSV Excel JMP Mac-Text Minitab PC-Text R SPSS TI-Calc Calculate the y-intercept and slope of the least-squares regression line using non-native grass biomass to predict chaparral shrubs biomass. Give your answers precise to three decimal places y-intercept mg slope0.401 Using the least-squares regression line, calculate the predicted value and residual value for the data point where the non- native grass biomass is equal to 57 and the chaparral shrubs biomass is equal to 27. Give your answers precise to three decimal places. predicted value: mg residual value: Select the statement that represents the correct interpretation of the residual value. OThe residual value measures the accuracy of the least-squares model. The residual value measures the variation in the response variable. The residual value measures how far away the observed value is from the predicted valueon_native_grass chaparral10 3726 399 6641 3763 2835 2757 2716 4123 5444 837 2650 2633 1343 1052 1541 2334 1597 567 693 072 1261 075 175 784 490 065 680 385 382 570 372 166 374 892 1473 1067 633 61 052 625 053 650 666 265 060 051 047 2250 857 21

Answer 1

To find the y-intercept and slope, we use the least-squares regression formula with the data provided. The predicted value for chaparral shrubs with 57 mg of non-native grass biomass is calculated using the regression line equation. The residual is the difference between the observed and predicted values for the chaparral shrubs biomass.

Step-by-step explanation:

To calculate the y-intercept and slope of the least-squares regression line for predicting the biomass of chaparral shrubs based on non-native grass biomass, we use the given information to establish a linear equation in the form of y = mx + b, where m is the slope and b is the y-intercept. However, it seems there was a mention of a slope of 0.401 but no intercept provided. Assuming the slope of 0.401 is correct and using the information provided, we'd need to use the data points to calculate the y-intercept.

Once we have both the y-intercept and the slope, to calculate the predicted value for a non-native grass biomass of 57 mg, we plug this value into the regression equation and calculate y. To find the residual value, we subtract this predicted value of chaparral shrubs from the actual observed value, which in the example is 27 mg. The residual value represents how far away the observed value is from the predicted value.

Answer 2

Step-by-step explanation:

answer is attached below