A. Calculate a 95% confidence interval for the coefficient of height, and interpret it in the context of the data. (df = 28)B. One tree in this sample is 79 feet tall, has a diameter of 11.3 inches, and is 24.2 cubic feet in volume. Determine if the model overestimates or underestimates the volume of this tree, and by how much. Timber yield is approximately equal to the volume of a tree, however, this value is difficult to measure without first cutting the tree down. Instead, othervariables, such as height and diameter, may be used to predict a tree's volume and yield. Researchers wanting to understand the relationship betweenthese variables for black cherry trees collected data from 31 such trees in the Allegheny National Forest, Pennsylvania. Height is measured in feet,diameter in inches (at 54 inches above ground), and volume in cubic feet.EstimateStd. Errort value Pr(>|t|)(Intercept)heightdiameter-57.998.64-6.710.000.340.132.610.014.710.2617.820.00

The given variables are volume in cubic feet, height in feet, and diameter in inches of trees.

A. Calculate a 95% confidence interval for the coefficient of height, and interpret it in the context of the data. (df = 28) B. One tree in this sample is 79 feet tall, has a diameter of 11.3 inches, and is 24.2 cubic feet in volume. Determine if the model overestimates or underestimates the volume of this tree, and by how much.

A. Calculate a 95% confidence interval for the coefficient of height, and interpret it in the context of the data. (df = 28) B. One tree in this sample is 79 feet tall, has a diameter of 11.3 inches, and is 24.2 cubic feet in volume. Determine if the model overestimates or underestimates the volume of this tree, and by how much.

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

Provide a detailed interpretation analysis of the regression results below. Pay attention to the main tested variables, model fit characteristics (R 2 ) and number of respondents in the sample. State what is dependent and what are independent variables. Was the hypotheses rejected or confirmed? a) H1: If a woman has a job she will have less children born b) H2: The younger a woman got married the more children she has c) H3: Education positively affects number of children to have
A traffic safety company publishes reports about motorcycle fatalities and helmet use. In the first accompanying data table, the distribution shows the proportion of fatalities by location of injury for motorcycle accidents. The second data table shows the location of injury and fatalities for 2061 riders not wearing a helmet. Complete parts (a) and (b) below. Click the icon to view the tables. (a) Does the distribution of fatal injuries for riders not wearing a helmet follow the distribution for all riders? Use α = 0.05 level of significance. What are the null and alternative hypotheses? O A. Ho: The distribution of fatal injuries for riders not wearing a helmet follows the same distribution for all other riders. H₁: The distribution of fatal injuries for riders not wearing a helmet does not follow the same distribution for all other riders. B. Ho: The distribution of fatal injuries for riders not wearing a helmet does not follow the same distribution for all other riders. H₁: The…
A packaging company fills bags so that each bags has an average weight of 250 grams. The owners take a sample of bags and records the weight (grams) of each. They found the following information: Five-Number Summary (in grams) Min 213.97 Q1 236.34 Q2 244.1 Q3 255.47 Max 272.5 75% of bags weigh more than which amount?
The data below are the shoot lengths (cm.) of Robusta coffee seedlings as affected by different periods of storage. Find out if there are significant differences in the effects of different periods of storage on the shoot lengths. (Note: CRD experiment) Solve for the; a. F computed b. Coefficient of Variation (CV), C. Standard error of the treatment means (S), d. standard error of difference between treatments (Sd) e. Make a Decision Treatments Replications 11 11 P1 10.1 9.2 9.5 P2 9.5 9.3 8.5 P3 8.7 9.2 7.5 P4 6.7 6.2 5.0
On average, a sample of n = 36 scores will provide a better estimate of the population mean than a sample of n = 49 scores from the same population.
Data on the price ($1000s) and the size (1000 ft2 sqaured) for 156 randomly selected houses that have been sold is summarized in the accompanying regression output and plots. Complete parts a and b a) Check the assumptions and conditions for inference. Select all that apply. A. The residuals look random. B. The residuals are nearly normal. C. The scatterplot looks straight enough. D. The residual plot and the scatterplot show consistent variability. E. None of the assumptions and conditions for inference are satisfied.
11. For temperature (x) and number of ice cream cones sold per hour (y). (65, 8), (70, 10), (75, 11), (80,13), (85, 12), (90, 16). Interpret the coefficient of determination. Optional Answers: 1. 88.2% of the variability in the number of cones sold is explained by the least-squares regression model. 2. 93.9% of the variability in the number of cones sold is explained by the least-squares regression model. 3. 88.2% of the variability in the temperature is explained by the least-squares regression model. 4. 93.9% of the variability in the temperature is explained by the least-squares regression model.
Several methods of estimating the number of seeds in soil samples have been developed by ecologists. An article gave the accompanying data on the number of seeds detected by the direct method and by the stratified method for 27 soil specimens. Specimen 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Direct 21 33 0 60 20 61 40 8 13 93 1 68 77 21 Stratified 8 37 8 57 53 61 28 8 8 100 0 57 68 53 Specimen 15 Find the test statistic. (Round your answer to two decimal places.) t = 16 17 18 19 20 21 22 23 24 25 26 27 Direct Find the df. (Round your answer down to the nearest whole number.) df = 33 0 37 17 93 1 40 21 0 8 13 Use technology to find the P-value. (Round your answer to four decimal places.) P-value = 17 40 Stratified 28 0 37 13 93 13 48 21 0 13 40 Do the data provide sufficient evidence to conclude that the mean number of seeds detected differs for the two methods? Test the relevant hypotheses using a = 0.05. (Use direct stratified.) 13 77
Construct a dot plot for the asphalt data.(In the article “Evaluation of Low-Temperature Properties of HMA Mixtures”, the following values of fracture stress (in megapascals) were measured for a sample of 24 mixtures of hot-mixed asphalt (HMA).30 75 79 80 80 105 126 138 149 179 179 191223 232 232 236 240 242 245 247 254 274 384 470
The level of cretaine phosphokinase (CPK) in blood samples measures the amount of muscle damage for athletes. At Jock State University, the level of CPK was determined for each of 25 football players and 15 soccer players before and after practice. The two groups of athletes are trained independently. The data summary is as follows : For football players: n=25 Before Practice After Practice Difference (Before-After) Mean 254.73 225.6 29.13 Standard deviation 115.5 132.6 21.00 For soccer players: n=15 Before Practice After Practice Difference (Before-After) Mean 177.1 173.8 3.3 Standard deviation 60.7 64.4 6.88 Assume that all the data above are normal, use the information above to answer problem (7) Construct a 95% Confidence Interval for the difference in mean CPK values for football players BEFORE and AFTER exercises.