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2 years ago

.−3(4x + 3) + 4(6x + 1) = 43 What is the solution?

Mathematics

1 answer:

maks197457 [2]2 years ago

6 0

Answer:

x = 4

Step-by-step explanation:

After you simplify the left side by eliminating parentheses and collecting terms, you have a 2-step linear equation.

-3(4x +3) +4(6x +1) = 43 . . . . . . given

-12x -9 +24x +4 = 43 . . . . . eliminate parentheses

12x-5 = 43 . . . . . . . . . . . collect terms (now a 2-step equation)

12x = 48 . . . . . . . . . . step 1, add the opposite of the unwanted constant

x = 4 . . . . . . . . . . . step 2, divide by the coefficient of x

The solution is x = 4.

Check

-3(4·4 +3) +4(6·4 +1) = 43 . . . . substitute for x

-3(16 +3) +4(24 +1) = 43

-3(19) +4(25) = 43

-57 +100 = 43 . . . . . true

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Which of the following scores has the better relative position ( as measured by the z score) a. A score of 53 on a test for whic

Kisachek [45]

Answer:

d. Cannot be determined with the information provided.

Step-by-step explanation:

Z-score:

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Finding the better relative position:

The score with the better relative position is the one with a higher z-score.

To find the z-score, the mean and the standard deviation is needed, and in this question, the standard deviation is not given, and thus, the correct answer is given by option d.

3 0

3 years ago

A study by Consumer Reports showed that 64% of supermarket shoppers believe supermarket brands to be as good as national name br

natima [27]

Answer:

Step-by-step explanation:

Given that:

A study is conducted and the study by Consumer Reports showed that 64% of supermarket shoppers believe supermarket brands to be as good as national name brands.

Thus; we formulate the null and the alternative hypotheses as follows:

The proportion is ; $\frac{64}{100}$ = 0.64

Null hypothesis: ${H_0}:p = 0.64$

The Null hypothesis states that there is no evidence that “the percentage of supermarket shoppers believes that the supermarket ketchup is good as the national brand ketchup differ form 64%”.

Alternative hypothesis: ${H_a}:p \ne 0.64H$

The Alternative hypothesis states that there is evidence that “the percentage of supermarket shoppers believes that the supermarket ketchup is good as the national brand ketchup differ form 64%”.

The proportion of the population = 0.64

The sample size n = 100

The number of shoppers = 52 stating that the supermarket brand was as good as the national brand

The sample proportion $\hat p = \frac{52}{100}$

$\hat p = 0.52$

The z - value is calculated by the formula:

$z = \dfrac{\hat p-p}{\frac{\sqrt{ p(1-p)}}{100 }}$

$z = \dfrac{0.52-0.64}{\frac{\sqrt{ 0.64(1-0.64)}}{100 }}$

$z = \dfrac{-0.12}{0.048 }}$

z = -2.50

Since z = -2.50

the p-value = 2P(Z ≤ -2.50)

p-value = 2 × 0.0062

The p-value = 0.0124

At significance level, ∝ = 0.05 ; The p-value = 0.0124

According to the rejection rule, if p-value is less than 0.05 then we will reject null hypothesis at ∝ = 0.05

Hence, the p-value =0.0124 < ∝ (=0.05)

According to the reject rule; reject null hypothesis.

Conclusion: There is no evidence at all that the percentage of supermarket shoppers believes that the supermarket ketchup is good as the national brand ketchup differ form 64%.

d) we know that the significance level of ∝ = 0.05

The value ${z__{0.05}}$ is obtained as:

$P\left( {\left| Z \right| \le z} \right) = 0.05$

Now; to determine Z ; we locate the probability value of 0.05 form the table of standard normal distribution. Then we proceed to the left until the first column is reached and the value is 1.90. Also , we move upward until we reach the top and the value is 0.06. Now; the intersection of the row and column results the area to the left of z

This implies that : $P(Z \leq -1.96)=0.05$

The critical value for left tail is -1.96 and the critical value for right tail is 1.96.

Conclusion:

The critical value is -1.96 and the value of test statistic is - 2.50. Here, we can see that the value of test statistic is lesser than the critical value. Hence, we can be concluded that there is evidence that reject the null hypothesis.

Therefore, Yes, the national brand ketchup manufacturer is pleased with the conclusion.

5 0

3 years ago

In circle o,find the value of x, rounded to the nearest tenth.

Gemiola [76]

Answer:

$\huge\boxed{x \approx 5.4}$

Step-by-step explanation:

We can break down this problem by first realizing different parts of the circle.

The line which is 8 units long is a chord of the circle.
The line that is 3.6 is almost the radius of the circle
The line that x sits on is the radius.

With this, we can find out if we find the radius of the circle, we have our answer.

We should also note that the angle formed by the 3.6 units long line and the chord is a right angle.

What we need is a way to find the radius of the circle. This will get us x. The radius of a circle will be the length of any line that starts from point O and ends at the circle edge.

If we draw a line connecting the end of the 3.6 line at point O to the end of the 8 unit long chord, we get a triangle! (Image attached for reference).

We can solve for the hypotenuse using the Pythagorean Theorem. This theorem states that:

$\displaystyle a^2 + b^2 = c^2$

Since we know one side is 3.6, we can use that as A. The second side will be 4 since the 3.6 line lies directly in the center of the chord = 8/2 = 4!

$3.6^2 + 4^2 = c^2$
$12.96+16=c^2$
$28.96=c^2$
$\sqrt{28.96} = c$
$5.4 \approx c$

Therefore, since this is the radius of the circle (also the hypotenuse), this can be said for any line that comes from point O onto the edge of the circle.

The line X does just that. Therefore, the value of x is also 5.4.

Hope this helped!