The pooled variance is used to calculate the test statistics for comparing two population means when the population variances are assumed to be unequal
It dissociates:
CH3COOH + H2O = CH3COO- + H3O +
You have the expression of Ka:
Ka = [CH3COO-] * [H3O +] / [CH3COOH]
1.8x10 ^ -5 = X ^ 2 / 0.5
It clears X = 0.003 M
So:
[H3O +] = 0.003 M
[OH-] = 10 ^ -14 / 0.003 = 3.33x10 ^ -12 M
pH = - log 0.003 = 2.52
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The pooled variance is used to calculate the test statistics for comparing two population means when...
An analyst wants to test a hypothesis on the means of two populations. She takes samples from each population. The variances of the population are not known, but are assumed to be equal. Statistics calculated from these samples are Sample 1 Average 1,053.6 Count 34 Sample 2 Average 1,079 Count 29 The pooled variance is calculated as 365.9 Based on this data calculate the t statistic to use in the hypothesis test. Enter your answer to 2 decimal places.
The degrees of freedom for the appropriate critical value with a hypothesis test comparing two population means with population variances that are unknown but assumed to be equal are determined by . Select one: True False
Comparing the means of two independent population when the population variances are known and unknownSuppose you conduct a study and intend to use a hypothesis test to compare the means of two independent populations. Your null hypothesis is that the two means are equal. That is, \(\mathrm{H}_{0}: \mu_{1}=\mu_{2}\), or equivalently, \(\mathrm{H}_{0}: \mu_{1}-\mu_{2}=0\). Following is a table of the information you gather. Assume the populations from which your samples are drawn are both normally distributed.Sample SizeSample MeanSample VarianceSample 1n_(1)=41bar(x)_(1)=14.3s_(1)^(2)=67.24Sample 2n_(2)=21bar(x)_(2)=13.6s_(2)^(2)=46.24
when variances between two samples are not equal in a paired sample t test, the pooled variance must be computed and used 8n place of the estimated standard error. t or f
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In comparing two population means, an unpaired test provides more precise results than a paired test because the unpaired test uses two independent samples while the paired test uses a single sample. True O False Question 2 1 pts When comparing two population means, if the variations which are unique to each population are very small compared to the variations which are common to both populations, it is reasonable to assume that the population standard deviations are not equal. O...
1. The T distribution can be use when comparing two population with population variance unknown. True False 2. You may use the Normal distribution when comparing two population with population variance known. True False