Is the variance for the amount of money, in dollars, that...

Is the variance for the amount of money, in dollars, that shoppers spend on Saturdays at the mall the same as the variance for the amount of money that shoppers spend on Sundays at the mall? Suppose that the Table 13.34 shows the results of a study.
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Key Concepts

F-Test for Equality of Variances

The F-test is a statistical procedure used to compare the variances of two independent samples. It involves calculating the ratio of the two sample variances and comparing it to a critical value from the F-distribution. This test helps determine whether any observed differences in variances are statistically significant.

Variance

Variance is a statistical measure that quantifies the spread or dispersion of a set of data points around their mean. It provides insight into the variability of the data, making it crucial in understanding how much individual observations differ from the average.

Hypothesis Testing

Hypothesis testing is a systematic method used in statistics to decide whether there is enough evidence in a sample to infer that a certain condition holds true for the entire population. In the context of comparing variances, it involves formulating a null hypothesis that the variances are equal and an alternative hypothesis that they are not.

Transcript

00:01 Okay, so for this it wants to know if the variance of the money spent in dollars is the same as the variance in the amount of money spent on saturdays and sundays.

00:13 So saturdays is these ones right here and then sundays is these here.

00:26 So what i have to do is, first of all this does take a little bit, but what i have to do is i have to find the mean of saturday.

00:35 So i'm going to total up all of saturday.

00:46 So 75 plus 18 plus 150 plus 94 plus 62 plus 73 plus 62 plus 0 plus 124 plus 50 plus 31 plus 118.

01:07 And that's 857 and then i'm going to divide it by 1, 2, 3, 4, 5, 6, so 12.

01:18 857 divided by 12 is 71 .426 repeating.

01:28 Then i'm going to find the mean of sunday.

01:32 So i have 44 plus 58 plus 61 plus 19 plus 99 plus 60 plus 89 plus 137 plus 82 plus 39 plus 127 plus 141 plus 73.

01:57 And that is 1029.

02:02 Divide that by 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13.

02:10 Divided by 13 and that is 79 .153 or actually 154 because i'm going to round that.

02:26 Alright, so then once i know the mean of saturday, what i'm going to do is i'm going to take each one of these numbers and i'm going to find the difference.

02:36 So for example, 75 minus 71 .426.

02:41 I'm going to square it and then i'm going to get a number...

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