25x89 divided by 1/4

You are conducting a left-tailed test of a claim about a population mean when sigma is unknown with a sample size of 7.

Artyom0805 [142]

<h3>Answer: -3.71</h3>

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Explanation:

You'll need to use a T table to answer this question. Your stats textbook should have such a table in the back appendix section.

If your textbook doesn't have the proper table, or you don't have your textbook with you, then I recommend searching online for "t table" and you should have tons of free options to choose from.

In the table you'll look for the degrees of freedom row 6, since the degrees of freedom are equal to n-1. In this case, n = 7.

In this row, locate the column labeled "alpha = 0.005" and you'll be looking at "one tail". The value in this row and column is roughly 3.707

Since we're doing a left tailed test and we want P(t < C) = 0.005, where C is the critical value we're after. This must mean C < 0. So C = -3.707 approximately. Round this to two decimal places and we end up with -3.71

4 0

3 years ago

What is the area of this trapezoid? Enter your answer in the box.

olga2289 [7]

The formula for area of a trapezoid is
$\frac{(b1 + b2) \times h}{2}$
so you add up the bottom base (17) and the top base (3) to get 20.
you then take the sum of the bases (20) times the height (8) to get 160.
lastly, you take 160 ÷ 2 to get your final answer, which is 80 (:

4 0

3 years ago

Read 2 more answers

Please help me answer what letter

Leona [35]

Answer:

3/2

Step-by-step explanation:

Basically just multiply 1/2 by numbers.

1/2 * 2 = 1

1/2 * 3 = 3/2

1/2 * 4 = 2

1/2 * 5 = 5/2

And so on.

3 0

3 years ago

LAST QUESTION ON MY TEST PLEASE HELP

Kipish [7]

Answer:

x = 8

Step-by-step explanation:

For this question, you can use power of a point, more specifically when two secants intersect in the interior of a circle. From this, you get the equation:

(7 + x)(12) = (10)(2x + 2)

You can simplify and solve:

84 + 12x = 20x + 20

84 = 8x + 20

64 = 8x

x = 8

4 0

2 years ago

In 2008 the Better Business Bureau settled 75% of complaints they received (USA Today, March 2, 2009). Suppose you have been hir

Ede4ka [16]

Answer:

Explained below.

Step-by-step explanation:

According to the Central limit theorem, if from an unknown population large samples of sizes n > 30, are selected and the sample proportion for each sample is computed then the sampling distribution of sample proportion follows a Normal distribution.

The mean of this sampling distribution of sample proportion is:

$\mu_{\hat p}= p$

The standard deviation of this sampling distribution of sample proportion is:

$\sigma_{\hat p}=\sqrt{\frac{p(1-p)}{n}}$

(a)

The sample selected is of size <em>n</em> = 450 > 30.

Then according to the central limit theorem the sampling distribution of sample proportion is normally distributed.

The mean and standard deviation are:

$\mu_{\hat p}=p=0.75\\\\\sigma_{\hat p}=\sqrt{\frac{p(1-p)}{n}}=\sqrt{\frac{0.75(1-0.75)}{450}}=0.0204$

So, the sampling distribution of sample proportion is $\hat p\sim N(0.75,0.0204^{2})$ .

(b)

Compute the probability that the sample proportion will be within 0.04 of the population proportion as follows:

$P(p-0.04$

$=P(-1.96$

Thus, the probability that the sample proportion will be within 0.04 of the population proportion is 0.95.

(c)

The sample selected is of size <em>n</em> = 200 > 30.

Then according to the central limit theorem the sampling distribution of sample proportion is normally distributed.

The mean and standard deviation are:

$\mu_{\hat p}=p=0.75\\\\\sigma_{\hat p}=\sqrt{\frac{p(1-p)}{n}}=\sqrt{\frac{0.75(1-0.75)}{200}}=0.0306$

So, the sampling distribution of sample proportion is $\hat p\sim N(0.75,0.0306^{2})$ .

(d)

Compute the probability that the sample proportion will be within 0.04 of the population proportion as follows:

$P(p-0.04$

$=P(-1.31$

Thus, the probability that the sample proportion will be within 0.04 of the population proportion is 0.81.

(e)

The probability that the sample proportion will be within 0.04 of the population proportion if the sample size is 450 is 0.95.

And the probability that the sample proportion will be within 0.04 of the population proportion if the sample size is 200 is 0.81.

So, there is a gain in precision on increasing the sample size.

6 0

3 years ago