A new vaccination is being used in a laboratory experiment to investigate whether it is effective. There are 288 subjects in the study. Is there sufficient evidence to determine if vaccination and disease status are related?
| Vaccination Status | Diseased | Not Diseased | Total |
|---|---|---|---|
| Vaccinated | 81 | 45 | 126 |
| Not Vaccinated | 54 | 108 | 162 |
| Total | 135 | 153 | 288 |
Step 1 of 8: State the null and alternative hypothesis.
Step 2 of 8: Find the expected value for the number of subjects who are vaccinated and are diseased. Round your answer to one decimal place.
Step 3 of 8: Find the expected value for the number of subjects who are vaccinated and are not diseased. Round your answer to one decimal place.
Step 4 of 8: Find the value of the test statistic. Round your answer to three decimal places.
Step 5 of 8: Find the degrees of freedom associated with the test statistic for this problem.
Step 6 of 8: Find the critical value of the test at the 0.025 level of significance. Round your answer to three decimal places.
Step 7 of 8: Make the decision to reject or fail to reject the null hypothesis at the 0.025 level of significance.
Step 8 of 8: State the conclusion of the hypothesis test at the 0.025 level of significance.
In: Statistics and Probability
an experiment was preformed under identical conditions as yours. The absorbance of the penny solution was recorded as 0.231 absorbance units. A calibration plot of absorbance vs concentration of cu(II) (mM) yielded the following trendily equations y= 11591x +.50
a. What is the concentration of the original penny solution?
b. How many grams of Cu are in this solution?
c. if the percent Cu was determined to be 2.70 percent what was the mass of the penny?
In: Chemistry
This is for my biochemistry lab, the experiment is dealing with trypsin and BPTI. I need to make a graph: plot the absorbance change per minute versus the BPTI concentration for each cuvette.
here are my cuvettes and amount of BPTI added to each
1- 0uL BPTI added
2- 10 uL BPTI added
3-20 uL BPTI added
4-30 uL BPTI added
5- 40 uL BPTI added
6- 50 uL BPTI added.
Each cuvette has a different amount of water and trypsin added to them, for a total volume of 100 uL in each cuvette.
I was give a sample of BPTI for which I had to find the concentration. Using the absorbance, I calculated that the concentration was 0.035mM. We then had to dilute this 10-fold, so to 0.0035mM.
I am not sure how to find the concentration of BPTI in each cuvette with this information. The molecular weight of BPTI is 6500. I don't know if that is needed.
I feel like this should be really easy, but I am having trouble doing this.
In: Chemistry
In an experiment involving the breaking strength of a certain type of thread used in personal flotation devices, one batch of thread was subjected to a heat treatment for 60 seconds and another batch was treated for 120 seconds. The breaking strengths (in N) of ten threads in each batch were measured. The results were
60 seconds: 43 52
52 58 49
52 41 52
56 58
120 seconds: 59 55
59 66 62
55 57 66
66 51
Let μXμX represent the population mean for threads treated for 120 seconds and let μYμY represent the population mean for threads treated for 60 seconds. Find a 99% confidence interval for the difference μX−μYμX−μY . Round down the degrees of freedom to the nearest integer and round the answers to three decimal places.
The 99% confidence interval is
In: Statistics and Probability
An experiment is performed to study the fatigue performance of a high strength alloy. The number of cycles to crack initiation is measured for twenty specimens over a range of applied pseudo-stress amplitude (PSA) levels. Use the data in the table provided to fit the following three regression models with y = Cycles and x = PSA (note the natural log transform of y for all models):
PSA (x) Cycles (y)
80, 97379
80, 340084
80, 246163
80, 239348
100, 34346
100, 23834
100, 70423
100, 51851
120, 9139
120, 9487
120, 8094
120, 17956
140, 5640
140, 3338
140, 6170
140, 5608
160, 1723
160, 3525
160, 2655
160, 1732
i. A simple linear regression model: lny=β0+β1∙x .
ii. A quadratic polynomial model: lny=γ0+γ1∙x+γ2∙x2 .
iii. A simple linear regression model with a logarithm transformation on PSA: lny=δ0+δ1∙ln(x) .
In: Statistics and Probability
A factorial experiment was designed to test for any significant differences in the time needed to perform English to foreign language translations with two computerized language translators. Because the type of language translated was also considered a significant factor, translations were made with both systems for three different languages: Spanish, French, and German. Use the following data for translation time in hours.
| Language | |||
|---|---|---|---|
| Spanish | French | German | |
| System 1 | 4 | 14 | 12 |
| 8 | 18 | 16 | |
| System 2 | 10 | 10 | 16 |
| 14 | 12 | 22 | |
Test for any significant differences due to language translator, type of language, and interaction. Use α = 0.05.
Find the value of the test statistic for language translator. (Round your answer to two decimal places.)
Find the p-value for language translator. (Round your answer to three decimal places.)
p-value =
State your conclusion about language translator.
Because the p-value > α = 0.05, language translator is not significant.Because the p-value ≤ α = 0.05, language translator is not significant. Because the p-value ≤ α = 0.05, language translator is significant.Because the p-value > α = 0.05, language translator is significant.
Find the value of the test statistic for type of language. (Round your answer to two decimal places.)
Find the p-value for type of language. (Round your answer to three decimal places.)
p-value =
State your conclusion about type of language.
Because the p-value > α = 0.05, type of language is significant.Because the p-value ≤ α = 0.05, type of language is not significant. Because the p-value > α = 0.05, type of language is not significant.Because the p-value ≤ α = 0.05, type of language is significant.
Find the value of the test statistic for interaction between language translator and type of language. (Round your answer to two decimal places.)
Find the p-value for interaction between language translator and type of language. (Round your answer to three decimal places.)
p-value =
State your conclusion about interaction between language translator and type of language.
Because the p-value > α = 0.05, interaction between language translator and type of language is not significant.Because the p-value ≤ α = 0.05, interaction between language translator and type of language is significant. Because the p-value > α = 0.05, interaction between language translator and type of language is significant.Because the p-value ≤ α = 0.05, interaction between language translator and type of language is not significant.
In: Statistics and Probability
An experiment is performed to study the fatigue performance of a high strength alloy. The number of cycles to crack initiation is measured for twenty specimens over a range of applied pseudo-stress amplitude (PSA) levels. Use the data in the table provided to fit the following three regression models with y = Cycles and x = PSA (note the natural log transform of y for all models):
PSA (x) Cycles (y)
80, 97379
80, 340084
80, 246163
80, 239348
100, 34346
100, 23834
100, 70423
100, 51851
120, 9139
120, 9487
120, 8094
120, 17956
140, 5640
140, 3338
140, 6170
140, 5608
160, 1723
160, 3525
160, 2655
160, 1732
i. A simple linear regression model: lny=β0+β1∙x .
ii. A quadratic polynomial model: lny=γ0+γ1∙x+γ2∙x2 .
iii. A simple linear regression model with a logarithm transformation on PSA: lny=δ0+δ1∙ln(x) .
In: Statistics and Probability
A manager of a large chain of appliance stores is planning to conduct a pricing experiment to determine the price elasticity of the chain’s line of microwave ovens. He plans to measure sales for the month of February, raise prices by 12 percent on March 15, and then measure sales for the month of April. Each sales measurement would take into account the total monthly microwave oven sales for all of the stores in his chain.
He has asked you to evaluate his research procedure and suggest any improvements. What would you suggest?
In: Accounting
Fertilizer: In an agricultural experiment, the effects of two fertilizers on the production of oranges were measured. Twelve randomly selected plots of land were treated with fertilizer A, and
7
randomly selected plots were treated with fertilizer B. The number of pounds of harvested fruit was measured from each plot. Following are the results.
| Fertilizer A | |||||
| 464 | 483 | 441 | 491 | 403 | 466 |
| 448 | 457 | 437 | 516 | 417 | 420 |
| Fertilizer B | ||||
|
362 |
414 |
412 |
398 |
382 |
|
377 |
393 |
|||
|
Part 1 of 3
Your Answer is correct
(a) Explain why it is necessary to check whether the populations
are approximately normal before constructing a confidence
interval.
Since the sample size is ▼small, it is necessary to check that the populations are approximately normal.
Part 2 of 3
Your Answer is correct
(b) Following are boxplots of these data. Is it reasonable to
assume that the populations are approximately normal?
400
420
440
460
480
500
520
540
360
370
380
390
400
410
420
It ▼is reasonable to assume that the populations are approximately normal.
Part: 2 / 3
2 of 3 Parts Complete
Part 3 of 3
(c) Construct an
80%
confidence interval for the difference between the mean yields for the two types of fertilizer. Let
μ1
denote the mean yield for fertilizer A. Use tables to find the
critical value and round the answer to one decimal place.
| The
80% confidence interval for the difference between the mean yields for the two types of fertilizer is<<−μ1μ2 . |
In: Statistics and Probability
1. In this experiment we injected the sample to be analyzed by Gas Chromatograph equipped with an FID (Flame Ionization Detector). The detector ionizes the sample as it reaches it, and the peak is proportional to the number of ions with a live flame. Explain in detail, why we need to run a standard when the GC is equipped with an FID detector to identify the component in a sample?
2. Gas Chromatography is another chromatography method you are learning about this semester. Construct a table comparing and contrasting the two other chromatography methods (TLC and LC). Point out to differences and similarities between each method and the GC method. Give at least 4 criteria of comparison.
3. During last week’s lab of distillation, many of you had difficulties getting the fractional distillation column to work properly. Specifically, the liquid started condensing at the top of the fractional column and the vapor did not distill over. The lab instructor suggested that changing the bead size (which was in the column) to a larger size might improve the outcome of the experiment. Is this suggestion valid? Would it help the process or is this suggestion wrong? Explain your answer.
In: Chemistry