In an experiment to determine the effect of nutrition on the attention spans of elementary school students, a group of 45 students is divided into three groups of 15, and randomly assigned to each of three meal plans: no breakfast, light breakfast, and full breakfast. Their attention spans, in minutes, were recorded. Say you want to test the hypothesis that the means of the attention spans are not all the same at a level of significance of 5%.

(a) (3 pts) What are the null and alternative hypotheses?

(b) (4 pts) Suppose that you find MSG=26 and MSE=3.1. Find the F-statistic, and estimate the p-value of your data using the F-table.

(c) (3 pts) Should you accept or reject? Explain.

An experiment was conducted to test the effect of a new drug on a viral infection. After the infection was induced in 100 mice, the mice were randomly split into two groups of 50. The control group received no treatment for the infection, while the other group received the drug. After a 30-day period, the proportions of survivors, p̂1 and p̂2, in the two groups were found to be 0.38 and 0.66, respectively. (a) Is there sufficient evidence to indicate that the drug is effective in treating the viral infection? Use α = 0.05. State the null and alternative hypotheses. H0: (p1 − p2) < 0 versus Ha: (p1 − p2) > 0 H0: (p1 − p2) = 0 versus Ha: (p1 − p2) > 0 H0: (p1 − p2) = 0 versus Ha: (p1 − p2) < 0 H0: (p1 − p2) = 0 versus Ha: (p1 − p2) ≠ 0 H0: (p1 − p2) ≠ 0 versus Ha: (p1 − p2) = 0 Find the test statistic and rejection region. (Round your answers to two decimal places. If the test is one-tailed, enter NONE for the unused region.) test statistic z = rejection region z > z < State your conclusion. H0 is rejected. There is sufficient evidence to indicate that the drug is effective in treating the viral infection. H0 is not rejected. There is insufficient evidence to indicate that the drug is effective in treating the viral infection. H0 is rejected. There is insufficient evidence to indicate that the drug is effective in treating the viral infection. H0 is not rejected. There is sufficient evidence to indicate that the drug is effective in treating the viral infection. (b) Use a 95% confidence interval to estimate the actual difference (p1 − p2) in the survival rates for the treated versus the control groups. (Round your answers to three decimal places.) to

The project is to "Design and build an experiment to verify the first law of thermodynamics by stirring air with an electric motor powered paddle, in a well-insulated container." We are planning on finding the work of the motor and seeing if it equal to the change in internal energy of the container. The only problem is that we are confused on how to find the internal energy. What would be the best/easiest way to solve this? Also since the containor is well insulated does that mean that the deltaQ would equal 0?

Thank you very much!

An experiment was carried out to investigate the effect of species (factor A, with

I = 4)

and grade (factor B, with

J = 3)

on breaking strength of wood specimens. One observation was made for each species—grade combination—resulting in SSA = 443.0, SSB = 424.6, and SSE = 125.4. Assume that an additive model is appropriate.

(a)

Test

H₀: α₁ = α₂ = α₃ = α₄ = 0

(no differences in true average strength due to species) versus

H_a: at least one α_i ≠ 0

using a level 0.05 test.

Calculate the test statistic. (Round your answer to two decimal places.)

f = 1

What can be said about the P-value for the test?

P-value > 0.1000.050 < P-value < 0.100    0.010 < P-value < 0.0500.001 < P-value < 0.010P-value < 0.001

State the conclusion in the problem context.

Reject H₀. The data does not suggest any difference in the true average strength due to species.Reject H₀. The data suggests that true average strength of at least one of the species is different from the others.    Fail to reject H₀. The data suggests that true average strength of at least one of the species is different from the others.Fail to reject H₀. The data does not suggest any difference in the true average strength due to species.

(b)

Test

H₀: β₁ = β₂ = β₃ = 0

(no differences in true average strength due to grade) versus

H_a: at least one β_j ≠ 0

using a level 0.05 test.

Calculate the test statistic. (Round your answer to two decimal places.)

f = 4

What can be said about the P-value for the test?

P-value > 0.1000.050 < P-value < 0.100    0.010 < P-value < 0.0500.001 < P-value < 0.010P-value < 0.001

State the conclusion in the problem context.

Reject H₀. The data does not suggest any difference in the true average strength due to grade.Fail to reject H₀. The data does not suggest any difference in the true average strength due to grade.    Reject H₀. The data suggests that true average strength of at least one of the grades is different from the others.Fail to reject H₀. The data suggests that true average strength of at least one of the grades is different from the others.

In order to compare a new variety of wheat with a standard, an experiment is used with six plots receiving the new variety and ten plots receiving the standard. The yields (t/ha) are as follows:

New variety: 2.6 2.1 2.5 2.4   1.9   2.3

Standard variety: 1.7 2.1 2.0   1.8 2.3   1.6   2.0   2.1 2.2 1.9

Question : (a) Identify the model for comparing the wheat yield?

(b) Is there evidence at the 5% significance level that the yield of the new variety is higher?

ANSWER QUESTION (a) necessary.

what is the main purpose of this experiment? and how to analyze the data, what are we trying to get? and how this experiment is working?

Kinetics of the Oxidation of Benzyl Alcohol

Objective: To study the kinetics of a reaction by a spectrometric method and how this relates to the dynamics of the system.

Theory

The oxidation of benzyl alcohol by the permanganate ion in acidic media is: 2MnO4 + 5C6H5CH2OH + 6H → 2Mn + 5C6H5CHO + 8H2O

The balanced equation does not provide any information concerning the reaction kinetics or dynamics. Indeed, the reaction does not progress to products by the simultaneous combination of all the reactants in their stoichiometric ratios. Rather, the reaction progresses through several simpler steps where the stoichiomentric coefficients indicate the order of the reaction with respect to that reactant. The mechanism describing the reaction often involves reactants not accounted for in the overall reaction. A typical mechanism1 for this oxidation involves a hydride transfer from the alcohol:

H+ + MnO4 ↔ HMnO4 {fast equilibrium}

HMnO4 + C6H5CH2OH → H2MnO4- + C6H5CHOH+ {slow}

C6H5CHOH+ → C6H5CHO + H+ {fast}

H2MnO4- → products {fast}

Notice the speed at which a step occurs is indicated and that the slowest step determines the overall rate of the reaction.

The above mechanism is conjecture until it is supported through experiment. Support for this mechanism is achieved by measuring the orders with respect to the reactants and demonstrating that these orders, in conjunction with the proposed rate determining step, agree with the suggested dynamics.

Experimental Setup

The chemical reaction studied will be the oxidation of benzyl alcohol by acid permanganate with the formation of benzaldehyde. According to the proposed mechanism, the kinetics should be of first order with respect to each reactant and will be determined by the spectrometric method using a Varian Spectrometer. A general schematic UV-Vis spectrometer is shown in figure 1. The basic parts of a spectrophotometer are a light source (often an incandescent bulb for the visible wavelengths, or a deuterium arc lamp in the ultraviolet), a holder for the sample, a diffraction grating or monochromator to separate the different wavelengths of light, and a detector. The method used in this experiment is a modification of the method proposed by Liu2.

The samples that you will prepare hold both the acid and alcohol concentrations in such excess that the pseudo first order kinetics is observed. You will be able to determine the order with respect to the remaining reactants from analysis of the rate constants as a function of concentration of the remaining reactants.

The samples that you will prepare hold both the acid and alcohol concentrations in such excess that the pseudo first order kinetics is observed. You will be able to determine the order with respect to the remaining reactants from analysis of the rate constants as a function of concentration of the remaining reactants.

Figure 1. General Schematic UV-Vis Spectrometer.

Procedure

Preparing the solution. Prepare 50 ml of 0.002 M potassium permanganate solution and store it in a brown bottle. The other solutions necessary for this experiment is a 0.04 M Benzyl alcohol and 1.4 M Sulfuric Acid, both of which are already prepared.

Preparing the sample. Absorption/time profiles on seven samples will be measured using the Varian UV-vis spectrometer. The concentrations of those samples are:

Data Analysis

Plot the Absorption/time profiles of your data. Manipulate the data so that you may acquire the rate constant associated with each sample run. It should be obvious that the reaction is first order with respect to the permanganate ion. Determine the orders with respect to the remaining reactants and verify the proposed mechanism.

in an experiment, 15.0 g of ice at -30 celsius is converted into steam with a temperature of 115 celsius. How much energy is required for this process? DHvap= 2260 J/g; DHfus= 334 J/g; cs(ice)= 2.06 J/(g celsius; cs(water)= 4.18 J/(g celsius; cs(steam)= 1.99 J/(g celsius))

In an experiment, a student was asked to measure the desity of an unknown liquid. He was given a small flask, which he found to have a mass of 32.6195 grams when empty. He filled the flask with water at 21.6 (0.997860 g/mL) degrees C and found the full flask to have a mass of 156.8995 grams. The student then emptied and dried the flask and then filled the flask with an unknown liquid. The mass of the flask filled with the unknown liquid was 134.2515 grams. Determine the volume of the flask and density of the unknown liquid.

An experiment was made to measure the mean number of axe strikes that is necessary to cut a tree trunk. A total of 16 identical tree trunks were cut by a randomly chosen person, and the following data (number of axe strikes) was collected: 52, 54, 56, 55, 57, 47, 53, 45, 46, 48, 55, 57, 51, 54, 56, 52. Is there sufficient evidence to conclude that the median number of strikes is 50?

An experiment was made to measure the mean number of axe strikes that is necessary to cut a tree trunk. A total of 16 identical tree trunks were cut by a randomly chosen person, and the following data (number of axe strikes) was collected: 52, 54, 56, 55, 57, 47, 53, 45, 46, 48, 55, 57, 51, 54, 56, 52. Is there sufficient evidence to conclude that the median number of strikes is 50?