I dont understand it :/
1 answer:
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Answer:
59.98
Step-by-step explanation:
To find the average of a set of numbers, we sum them all together and divide them by the size of the set. Here, we start out with 11 IQ scores. We don't know what they are, but we can still set up an equation with the information we do have. Let's call the sum of those 11 score <em>s</em>. The average must be s/11, which we know is 101.5. With that, we can set up and solve and equation for <em>s</em>:
Let's call the score of the reality TV star <em>r</em>. If we add their score to the set, we now have <em>12</em> scores. The sum of those scores is gonna be the sum of the previous scores, 1116.5, plus the reality TV star's score, r. To find the average, we divide the sum by 12. Finally, we're told that this average is exactly 98.04. Putting all of this into an equation gives us
We can now solve for r algebraically, first by multiplying both sides by 12:
And then subtracting 1116.5 from both sides:
Answer:
The critical values for α = 0.10 are t=±1.7341.
Step-by-step explanation:
The critical values for a two tailed test are the values of t that are placed in the limit of the significance level. If the test statistic t is greater than this critical values, the null hypothesis is rejected.
To determine this values, we first divide the significance level by 2. With a t-table or app, we can determine the t values for P(x>|t|)=α/2=0.05.
In this case, for a degrees of freedom DF=20-2=18, we have the test statistic t=±1.7341 that satisfies the condition.
Solution of the hypothesis test
In this problem we want to prove if the slope of the regression model is different from 0, by means of a hypothesis test.
First, we state the null and alternative hypothesis:
The significance level is .
The degrees of freedom for a simple regression model is:
The standard error estimated of the slope is 0.0053.
The test statistic t is calculated as:
The P-value for a two-tailed test for a t=4.0377 and DF=18 is:
The P-value is smaller than the significance level, so the effect is statistically significant. The null hypothesis is rejected.
