What is the answer?! Pls help!

Emissions of sulfur dioxide by industry sett off chemical changes in the atmosphere that result in "acid rain". The acidity of l

horsena [70]

Answer:

Case n =5

$z=\frac{4.8-5}{\frac{0.5}{\sqrt{5}}}=-0.894$

Case n =15

$z=\frac{4.8-5}{\frac{0.5}{\sqrt{15}}}=-1.549$

Case n = 40

$z=\frac{4.8-5}{\frac{0.5}{\sqrt{40}}}=-2.530$

P value

Case n =5

$p_v =P(z$

Case n =15

$p_v =P(z$

Case n =40

$p_v =P(z$

Step-by-step explanation:

Data given and notation

$\bar X=4.8$ represent the sample mean

$\sigma=0.5$ represent the population standard deviation

$n$ sample size

$\mu_o =5$ represent the value that we want to test

$\alpha$ 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)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean is lower than 5, the system of hypothesis would be:

Null hypothesis: $\mu \geq 5$

Alternative hypothesis: $\mu < 5$

Since we know the population deviation, is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

z-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".

Calculate the statistic

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

Case n =5

$z=\frac{4.8-5}{\frac{0.5}{\sqrt{5}}}=-0.894$

Case n =15

$z=\frac{4.8-5}{\frac{0.5}{\sqrt{15}}}=-1.549$

Case n = 40

$z=\frac{4.8-5}{\frac{0.5}{\sqrt{40}}}=-2.530$

P-value

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

Case n =5

$p_v =P(z$

Case n =15

$p_v =P(z$

Case n =40

$p_v =P(z$

5 0

3 years ago

Please help me answer this question

vfiekz [6]

9514 1404 393

Answer:

the correct answer is marked

Step-by-step explanation:

The graph ranges vertically between 9 and 15, starting at 9 (the minimum) when x=0. The minimum appears again at x=350.

This means the vertical offset is (9+15)/2 = 12, and the amplitude is (15 -9)/2 = 3. The period is 350, so the coefficient of x is (2π/350). All of the answer choices agree on these parameters.

So, the selection comes down to an understanding of how the sine and cosine curves vary. The sine curve starts at zero and increases from there. The cosine curve starts at its maximum (1) and decreases. Here, the curve starts a its minimum and increases, so could be the opposite of the cosine function.

y = -3cos(2πx/350) +12 . . . . . . matches choice C

5 0

3 years ago

Multiple Choice What is the sum of five-sixths + start fraction 2 over 3 end fraction? A. one and one-third B. One and one half

polet [3.4K]

Answer:

B

Step-by-step explanation:

$\frac{5}{6} +\frac{2}{3} \\\\=\frac{5}{6}+\frac{2*2}{2*3} \\\\=\frac{5}{6}+\frac{4}{6} \\\\=\frac{5+4}{6} \\\\=\frac{9}{6} \\\\=\frac{3*3}{3*2} \\\\=\frac{3}{2}$