Which of the following is an open statement?

The bacterial strain Acinetobacter has been tested for its adhesion properties. A sample of five measurements gave read- ings of

oksian1 [2.3K]

Answer:

Part a

We need to conduct a one tailed test

We need to conduct a hypothesis in order to check if the mean is higher than 2.5, the system of hypothesis would be:

Null hypothesis: $\mu \leq 2.5$

Alternative hypothesis: $\mu > 2.5$

Part b: Calculate the statistic

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

$z=\frac{3.372-2.5}{\frac{0.66}{\sqrt{5}}}=2.954$

Part c :P-value

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

$p_v =P(z>2.954)=0.0016$

Conclusion

If we compare the p value and the significance level assumed $\alpha=0.01$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, we can conclude that the true mean is higher than 2.5 at 1% of signficance.

Step-by-step explanation:

a. Should the alternative hypothesis be one-sided or two-sided?

b. Test the hypothesis that the mean adhesion is 2.5 dyne-cm².

c. What is the P-value of the test statistic?

Data given and notation

Data: 2.69, 5.76, 2.67, 1.62 ,4.12

We can calculate the sample mean with this formula:

$\bar X= \frac{\sum_{i=1}^n X_i}{n}$

$\bar X=3.372$ represent the sample mean

$\sigma=0.66$ represent the population standard deviation

$n=5$ sample size

$\mu_o =2.5$ represent the value that we want to test

$\alpha=0.01$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

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

Part a: State the null and alternative hypotheses.

We need to conduct a one tailed test

We need to conduct a hypothesis in order to check if the mean is higher than 2.5, the system of hypothesis would be:

Null hypothesis: $\mu \leq 2.5$

Alternative hypothesis: $\mu > 2.5$

If we analyze the size for the sample is < 30 but we know the population deviation so 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".

Part b: Calculate the statistic

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

$z=\frac{3.372-2.5}{\frac{0.66}{\sqrt{5}}}=2.954$

Part c :P-value

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

$p_v =P(z>2.954)=0.0016$

Conclusion

If we compare the p value and the significance level assumed $\alpha=0.01$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, we can conclude that the true mean is higher than 2.5 at 1% of signficance.

8 0

3 years ago

What is the square root of 36 over 49

Ghella [55]

$\sqrt{\frac{36}{49}}= \frac{6}{7}$

4 0

3 years ago

Answer and working out please!

frosja888 [35]

Answer:

17.0710678119 and 2.92893218813

Step-by-step explanation:

Theoretically, the wire should come out to be x+y=80,

and the sum of the areas of the squares should be (x/4)^2+(y/4)^2=300.

x/4 and y/4 being the length of one side of the square, we would then square that to find the area. The total wire is all x+y=80. X being one part and Y being the other.

Theoretically, using systems. i found the answers: 68.2842712474619,11.715728752538098

Again, these numbers are very large, and I they actually do both add up to each amount basically perfectly. If your teacher is asking for a rounded answer, that would've been helpful to know. But again, theoretically, those are the answers.

3 0

4 years ago

A box contains 12 balls of which 5 red, and 7 arw blue, if 4 balls are drawn from the box, in how many ways can this be done of.

Natali [406]

Answer:

B . all are blue

Step-by-step explanation:

at least they will be almost equal . not sure

7 0

3 years ago

Use the sample data and confidence level given below to complete parts (a) through (d).

Readme [11.4K]

Answer:

A

Step-by-step explanation:

yes because 3+2 +5 = 923x which is the inversde ratio of a triangle. This leads us to 1 half of 3.14, once we have 3.14, divide it by 70594. Now, you get 59.4.

Hope this helped!

8 0

3 years ago