Aboard is 4 ft 8 in long how long is the board in meters

Two different types of polishing solutions are being evaluated for possible use in a tumble-polish operation for manufacturing i

Nina [5.8K]

Answer:

$z=\frac{0.843-0.653}{\sqrt{0.748(1-0.748)(\frac{1}{300}+\frac{1}{300})}}=5.358$

$p_v =2*P(Z>5.358) = 4.2x10^{-8}$

Comparing the p value with the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can say that we have singificantly differences between the two proportions.

Step-by-step explanation:

Data given and notation

$X_{1}=253$ represent the number with no defects in sample 1

$X_{2}=196$ represent the number with no defects in sample 1

$n_{1}=300$ sample 1

$n_{2}=300$ sample 2

$p_{1}=\frac{253}{300}=0.843$ represent the proportion of number with no defects in sample 1

$p_{2}=\frac{196}{300}=0.653$ represent the proportion of number with no defects in sample 2

z would represent the statistic (variable of interest)

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

$\alpha=0.05$ significance level given

Concepts and formulas to use

We need to conduct a hypothesis in order to check if is there is a difference in the the two proportions, the system of hypothesis would be:

Null hypothesis: $p_{1} - p_2}=0$

Alternative hypothesis: $p_{1} - p_{2} \neq 0$

We need to apply a z test to compare proportions, and the statistic is given by:

$z=\frac{p_{1}-p_{2}}{\sqrt{\hat p (1-\hat p)(\frac{1}{n_{1}}+\frac{1}{n_{2}})}}$ (1)

Where $\hat p=\frac{X_{1}+X_{2}}{n_{1}+n_{2}}=\frac{253+196}{300+300}=0.748$

z-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.

Calculate the statistic

Replacing in formula (1) the values obtained we got this:

$z=\frac{0.843-0.653}{\sqrt{0.748(1-0.748)(\frac{1}{300}+\frac{1}{300})}}=5.358$

Statistical decision

Since is a two sided test the p value would be:

$p_v =2*P(Z>5.358) = 4.2x10^{-8}$

Comparing the p value with the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can say that we have singificantly differences between the two proportions.

5 0

3 years ago

28.74% of 676.87 to 2 decimal places pls help

gregori [183]

Answer:

the answer of this question is = 194.53

8 0

3 years ago

Can somebody pls help mee

Leto [7]

Answer:

the answer is 8

Step-by-step explanation:

add all four in n the half of the others 2 =1

8 0

3 years ago

Assume you wanted to save $2,000 to buy a used car 18 months from now. How much money do you need to save every week to accompli

Evgesh-ka [11]

$500 as you take $2000/4 weeks

3 0

3 years ago

!!!!!!!!!!!!!!!! URGENT !!!!!!!!!!!!!!!!!! 1.2 Learning Checkpoint

Grace [21]

Answer: Try to figure it out first. If you can't, then you haven't learned the material and you won't be able to understand subsequent lessons.

Step-by-step explanation:

Question 1 checks that you know several things:

● Point (5,8) means x=5 and y=8.

● Which number is the y intercept in equation y = m x + b.

m is NOT the y intercept.

b IS the y intercept.

Guess which is the slope...

● The y intercept is value of y when x is zero. But m times zero is zero, no matter what m is, so m can't be the y intercept. On the other hand, m x + b evaluates to b when x is zero.

● The meaning of an inequality and how it is graphed:

A solid line means the line is included in the graph (≤ or ≥).

A dotted line means the line is not included (< or >).

The shaded area indicates points in that area are in the solution set of the inequality.

● To see if point (A,B) is in the solution set, substitute A for x and B for y, and see if the result is true.

Say (A,B) = (5,6), and the statement is y < 2x + 3. You substitute A (5) for x and evaluate the right hand side to a number (13), and substitute B (6) for y on the left hand side to give a statement about two numbers: 6 < 13. If the statement is true, then (A,B) is in the solution set.

Then the region containing (A,B) will be shaded (inequality), or a solid line (equation).

Question 2 tries to see if you realize you can't draw a line between two points without first plotting both points.

Question 3 checks to see if you know how to tell if an equation matches a line on graph paper. You can look at the line, find the y intercept (b) and the slope (m), and look for an equation y = m x + b.

For instance, the red line crosses the y axis at (0,4), x = 0 (always true for a y intercept), and y = 4. So the equation for the red line must be

y = m x + 4. If you substitute (0,4), you get 4 = m × 0 + 4 = 4, a true statement.

You can figure the slope of the red line as m = rise/run. The answer is m=2, so the equation is y = 2x+4.

Or you can just check all of the choices. Takes longer but you don't have to know how to find slope.

But after doing this (or even without doing it), you check to see if a few points from the line make the equation true. The red line includes (-4,-4). So check -4 = 2(-4) + 4. Since -8+4 is -4, the result is true. Also check (0,4) and (-2,0) because they are easy to do. 4 = 2(0)+4, true, and 0 = 2(-2) + 4, true. y = 2x + 4 is the equation of the red line.

If the check fails, then either you don't know how to read the slope and y intercept, or else you don't know how to substitute x and y into the equation.

Another way to eliminate incorrect choices quickly is to substitute (-3,-2), x = -3, y = -2, into each pair. If either equation evaluates to false, eliminate that choice. But that might not eliminate all but one choice, so you need to test all of them.

The last question checks to see if you can figure out which axis is x and which is y, and if you know (-3,-2) means x=-3, y=-2, and not x=-2, y=-3.

7 0

4 years ago