Please help me anyone, please

vlabodo [156]

The answer would be letter b

6 0

2 years ago

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

For each model below write the portion of the grid that is shaded as a percent and as a fraction. EXPLAIN.

Rudik [331]

Answer:

Just find the area of each shape .fir the first triangle it will be (0.5 x6 x6) so the answer is 18 . So the shaded part is 18 out of 100 or 18% . And so on for the trapezoid and the combined figure of square and triangle together

Step-by-step explanation:

5 0

3 years ago

Huang eats a salad for breakfact,a burger for lunch,then a saled for dinner.how many burger has Huang eaten if he had 71 salads

sweet [91]

35 because if you half the amount of salads he's eaten (seeing as he eats one burger for every two salads) then the extra one is the first salad in the cycle.

4 0

3 years ago

What is the volume of a box with a height of 3/2 inches, a length of 7/2 inches, and a width of 5/2 inches.

JulsSmile [24]

Answer:

13.125 cubic inches

Step-by-step explanation:

Volume of box is 3/2 X 7/2 X 5/2 = 105/8 = 13 1/8 = 13.125 cubic inches

4 0

3 years ago