8|7+(-10)<br> Simplify:<br> 2-32

An important factor in selling a residential property is the number of times real estate, agents show a home. A sample of 21 hom

Natalka [10]

Using the t-distribution to build the 99% confidence interval, it is found that:

The margin of error is of 3.64.

The 99% confidence interval for the population mean is (19.36, 26.64).

<h3>What is a t-distribution confidence interval?</h3>

The confidence interval is:

$\overline{x} \pm t\frac{s}{\sqrt{n}}$

In which:

$\overline{x}$ is the sample mean.

t is the critical value.

n is the sample size.

s is the standard deviation for the sample.

The critical value, using a t-distribution calculator, for a two-tailed 95% confidence interval, with 21 - 1 = 20 df, is t = 2.086.

The other parameters are given as follows:

$\overline{x} = 23, s = 8, n = 21$

The margin of error is given by:

$M = t\frac{s}{\sqrt{n}} = 2.086\frac{8}{\sqrt{21}} = 3.64$

Hence the bounds of the interval are:

$\overline{x} - M = 23 - 3.64 = 19.36$

$\overline{x} + M = 23 + 3.64 = 26.64$

The 99% confidence interval for the population mean is (19.36, 26.64).

More can be learned about the t-distribution at brainly.com/question/16162795

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7 0

2 years ago

Darla wants to buy a dress for $20 and some shirts for $12 each. She has $80. Write and solve an inequality to find the number o

marishachu [46]

Answer:

5 shirts for 12 is 60 dollars

20 dollar dress plus 60 is 80

Step-by-step explanation:

4 0

3 years ago

6) 2(n + 5) = -2<br> help i wasn’t paying attention in my google meet

bonufazy [111]

Answer: the answer is -6

2(n+5) = -2

2n + 10 = -2

2n = -2 - 10

2n = -12

2n *1/2 = -12 * 1/2 = -6

n = -6

5 0

3 years ago

Read 2 more answers

Fowle Marketing Research Inc., bases charges to a client on the assumption that telephone surveys can be completed in a mean tim

sergejj [24]

Answer:

a) Null hypothesis: $\mu \leq 15$

Alternative hypothesis: $\mu > 15$

b) $t=\frac{17-15}{\frac{4}{\sqrt{35}}}=2.958$

c) $p_v =P(t_{34}>2.958)=0.0028$

d) If we compare the p value and the significance level given $\alpha=0.01$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, so we can conclude that the true mean is higher than 15 at 1% of signficance.

Step-by-step explanation:

Data given and notation

The sample mean is given by:

$\bar X = \frac{\sum_{i=1}^n X_i}{n}$

And the sample deviation is:

$s = \sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}$

$\bar X=17$ represent the sample mean

$s=4$ represent the sample standard deviation

$n=35$ sample size

$\mu_o =15$ represent the value that we want to test

$\alpha=0.01$ represent the significance level for the hypothesis test.

z would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

Part a State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean is less or equal than 15, the system of hypothesis would be:

Null hypothesis: $\mu \leq 15$

Alternative hypothesis: $\mu > 15$

Since we don't know the population deviation, is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Part b Calculate the statistic

We can replace in formula (1) the info given like this:

$t=\frac{17-15}{\frac{4}{\sqrt{35}}}=2.958$

Part c P-value

The degrees of freedom are given by:

$df = n-1= 35-1=34$

Since is a right tailed test the p value would be:

$p_v =P(t_{34}>2.958)=0.0028$

Part d Conclusion

If we compare the p value and the significance level given $\alpha=0.01$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, so we can conclude that the true mean is higher than 15 at 1% of signficance.

7 0

3 years ago

2x - 6y = 12<br> 2x – 4y = 8

Alenkasestr [34]

Answer:

true

Step-by-step explanation:

7 0

3 years ago

8|7+(-10) Simplify: 2-32