An experiment is to be carried out to determine the optimal
combination of microwave oven
settings for microwave popcorn. Cooking time has three possible
settings (3,4, and 5 minutes)
and cooking power has two settings (low power, high power). The
response (to be minimized)
is the number of burned plus the number of unpopped kernels.
a. Identify the experimental unit.
b. Identify the experimental factor(s), levels, and any
factor-level combinations if present
In: Statistics and Probability
In an experiment to investigate the performance of four
different brands of spark plugs intended for use on a 125-cc
motorcycle, five plugs of each brand were tested, and the number of
miles (at a constant speed) until failure was observed. A partially
completed ANOVA table is given.
Fill in the missing entries, and test the relevant hypotheses using
a .05 level of significance. (Give the answer to two decimal
places.)
| Source of Variation |
df | Sum of Squares |
Mean Square |
F |
| Treatments | 1 | 2 | 3 | 4 |
| Error | 5 | 236682.04 | 6 | |
| Total | 7 | 313520.78 | ||
In: Statistics and Probability
The table below lists the observed frequencies for all four categories for an experiment.
__________________________
Category 1 2 3 4
___________________________
Observed Frequency 12 14 18 16
_____________________________
The null hypothesis for the goodness-of-fit test is that the proportion of all elements of the population that belong to each of the four categories is the same. What is the expected frequency for the second category?
The null hypothesis for the goodness-of-fit test is that the proportion of all elements of the population that belong to each of the four categories is the same. The expected frequencies for the four categories are:
Category 1:
Category 2:
Category 3:
Category 4:
The null hypothesis for the goodness-of-fit test is that the proportion of all elements of the population that belong to each of the four categories is the same. What are the degrees of freedom for this test?
The null hypothesis for the goodness-of-fit test is that the proportion of all elements of the population that belong to each of the four categories is the same. The significance level is 1%. What is the critical value of chi-square? 12.838 13.277 14.860 11.345
The null hypothesis for the goodness-of-fit test is that the proportion of all elements of the population that belong to each of the four categories is the same. What is the value of the test statistic, rounded to three decimal places?
In: Statistics and Probability
Pete is doing a science-experiment and have decided to work on it until it succeeds. The chance of success on any given day is 0.001. Let X be the number of days until he succeeds. Which probability distribution does X have? What is E(X)? What is the probabilty of Pete succeeding in his first year? If he doesn't succeed the first year, what's the probability of success in the second year?
In: Statistics and Probability
An experiment is to flip a coin until a head appears for the first time. Assume the coin may be biased, i.e., assume that the probability the coin turns up heads on a flip is a constant p (0 < p < 1). Let X be the random variable that counts the number of flips needed to see the first head.
(a) Let k ≥ 1 be an integer. Compute the probability mass function (pmf) p(k) = P(X = k).
(b) If p = 1/3 compute P(2 ≤ X < 4) and P(1 < X < 3).
(c) If p = 1/3 compute P(X > 2).
(d) If p = 1/2 compute P(X is even).
In: Statistics and Probability
a chem 1515 student does the same experiment as the one you will be conducting this week but at a different temperature. She mixes 5.00 mL of 1.00 x 10-3 M solution of Fe(NO3)3 with 5.00 mL of 1.00 x 10-3 M KSCN solution. She finds out the equilibrium concentration of FeSCN2+ at theis condition to be 2.5 x 10-5 M. What is the value of the equilibrium constant for the reaction? Fe3+ (aq) + SCN- (aq) <--> FeSCN2+ (aq)
In: Chemistry
An experiment was conducted to investigate the effect of extrusion pressure (P) and temperature at extrusion (T) on the strength y of a new type of plastic. Two plastic specimens were prepared for each of five combinations of pressure and temperature. The specimens were then tested in a random order and the breaking strength for each specimen was recorded. The independent variables were coded (transformed) as follows to simplify the calculations: x1= (P-200)/10, x2= (T-400)/25. The n=10 data points are listed in the table:
y X1 X2
5.2 -2 2
5 -2 2
0.3 -1 -1
-0.1 -1 -1
-1.2 0 -2
-1.1 0 -2
2.2 1 -1
2 1 -1
6.2________2 ________2
6.1 2 2
!
In: Statistics and Probability
An experiment was conducted to see the effectiveness of two
antidotes to three different doses of a toxin. The antidote was
given to a different sample of participants five minutes after the
toxin. Thirty minutes later the response was measured as the
concentration in the blood. What can the researchers conclude with
an α of 0.01?
| Dose | |||
| Antidote | 5 | 10 | 15 |
| 1 | 0.6 6.5 1.1 |
2.1 1.5 2.4 |
3.1 4.1 5.9 |
| 2 | 1.1 1.2 1.1 |
1.7 1.3 1.5 |
2.1 3.1 2.1 |
a) What is the appropriate test statistic?
---Select--- na one-way ANOVA within-subjects ANOVA two-way
ANOVA
b) Obtain/compute the appropriate values to make a
decision about H0.
Antidote: critical value = ; test
statistic =
Decision: ---Select--- Reject H0 Fail to reject H0
Dose: critical value = ; test statistic
=
Decision: ---Select--- Reject H0 Fail to reject H0
Interaction: critical value = ; test
statistic =
Decision: ---Select--- Reject H0 Fail to reject H0
c) Compute the corresponding effect size(s) and
indicate magnitude(s).
Antidote: η2
= ; ---Select--- na trivial effect small
effect medium effect large effect
Dose: η2
= ; ---Select--- na trivial effect small
effect medium effect large effect
Interaction: η2
= ; ---Select--- na trivial effect small
effect medium effect large effect
d) Make an interpretation based on the
results.
There is an antidote difference in blood concentration.
There is no antidote difference in blood concentration.
There is a dose difference in blood concentration.
There is no dose different in blood concentration.
There is an antidote by dose interaction in blood concentration.
There is no antidote by dose interaction in blood concentration.
In: Statistics and Probability
An experiment examined the impact of THC (the active ingredient in marijuana) on various physiological and psychological variables. The study recruited a sample of 18 young adults who were habitual marijuana smokers. Subjects came to the lab 3 times, each time smoking a different marijuana cigarette: one with 3.9% THC, one with 1.8% THC, and one with no THC (a placebo). The order of the conditions was randomized in a double-blind design.At the start of each session, no subject reported being “high.” After smoking the cigarette, participants rated how “high” they felt, using a positive continuous scale (0 representing not at all “high”). For the placebo condition, participants reported a mean “high” feeling of 11.3, with a standard deviation of 15.5. Is there evidence of a significant placebo effect, with subject feeling significantly “high” after smoking a placebo marijuana cigarette?
**********************PLEASE SHOW WORK!!!!*******************************
What is the appropriate statistic to test this hypothesis? What is its value?
What is the P-value for the appropriate test? Specify the distribution used and all relevant parameters.
In: Statistics and Probability
An experiment was planned to compare the mean time (in days) required to recover from a common cold for persons given a daily dose of 4 milligrams (mg) of vitamin C, μ2, versus those who were not, μ1. Suppose that 32 adults were randomly selected for each treatment category and that the mean recovery times and standard deviations for the two groups were as follows.
Conduct the statistical test of the null hypothesis in part (a) and state your conclusion. Test using
α = 0.05.
(Round your answer to two decimal places.)
Find the test statistic.
z =
Find the rejection region. (Round your answers to two decimal places. If the test is one-tailed, enter NONE for the unused region.)
z > z <
| No
Vitamin Supplement |
4
mg Vitamin C |
|
|---|---|---|
| Sample Size | 32 | 32 |
| Sample Mean | 6.7 | 5.5 |
| Sample Standard Deviation | 2.7 |
1.3 |
In: Statistics and Probability