If ∠1≅∠2, then __

A manufacturer must test that his bolts are 4.00 cm long when they come off the assembly line. He must recalibrate his machines

storchak [24]

Answer:

The null hypothesis is $H_o: \mu = 4$ .

The alternate hypothesis is $H_a: \mu \neq 4$

The pvalue of the test is 0.0182 < 0.05, which means that there is sufficient evidence to show that the manufacturer needs to recalibrate the machines.

Step-by-step explanation:

A manufacturer must test that his bolts are 4.00 cm long when they come off the assembly line.

This means that the null hypothesis is that they are 4.00 cm long, that is:

$H_o: \mu = 4$

At the alternate hypothesis we test if it is different. So

$H_a: \mu \neq 4$

The test statistic is:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

In which X is the sample mean, $\mu$ is the value tested at the null hypothesis, $\sigma$ is the standard deviation and n is the size of the sample.

4 is tested at the null hypothesis:

This means that $\mu = 4$

After sampling 196 randomly selected bolts off the assembly line, he calculates the sample mean to be 4.14 cm.

This means that $n = 196, X = 4.14$

He knows that the population standard deviation is 0.83 cm.

This means that $\sigma = 0.83$

Value of the test statistic:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

$z = \frac{4.14 - 4}{\frac{0.83}{\sqrt{196}}}$

$z = 2.36$

Pvalue of the test and decision:

The pvalue of the test is the probability that the sample mean is different by at least 4.14 - 4 = 0.14 from the target value, which is P(|z| > 2.36), which is 2 multiplied by the pvalue of z = -2.36.

Looking at the z-table, z = -2.36 has a pvalue of 0.0091

2*0.0091 = 0.0182

The pvalue of the test is 0.0182 < 0.05, which means that there is sufficient evidence to show that the manufacturer needs to recalibrate the machines.

5 0

2 years ago

744 ÷ 40 in long division

wariber [46]

18.5 would be the answer and here’s my work

7 0

2 years ago

The real numbers x for which |x-19| = - (x-19) are?

Novosadov [1.4K]

Answer:

x = 19

|19-19|=0

-(19-19)=0

8 0

3 years ago

Please try your best and show your work and I will give brainliest!

dimulka [17.4K]

Answer:

Part A: impossible

Part B: Either equal or blue

Part C: 9 green and 2 blue were added

Step-by-step explanation:

Part A:

The only colors included in this problem are red, blue, and green. There is no black colored pencil, therefore, it is impossible to get one from the box.

Part B:

I'm not sure what you're asking in this question, but I will give you the two choices. If it is before the additional 11 colored pencils are added to the box, the chance of drawing a red and the chance of drawing a blue will be equal, because both of them have 11 of each color. If it is after the additional 11 colored pencils are added to the box, then the chance of drawing a blue colored pencil will be greater than the chance of drawing a red colored pencil. After the 11 colored pencils are added, there are 13 blue and 11 red. The blue is greater.

Part C:

The least number of green colored pencils added has to be 9, because the chance of drawing a green pencil is now greater than the chance of drawing a red pencil. If we add 8 more green pencils, the likelihood would be the same. Therefore, the number of green colored pencils added has to be at least 9. If we have the last 2 colored pencils be blue, then there would be 11 red, 13 blue, and 12 green. This fits all the conditions, therefore, adding 9 green colored pencils and 2 blue colored pencils is the answer.

I hope this helps and please mark me as brainliest!

5 0

2 years ago

Precalc Help me Please

Likurg_2 [28]

We just need to solve for y when x = -2

Solution:

y = 2|-2 + 1|

y = 2|-1|

y = 2(1)

y = 2

Therefore, the answer is Option 3

Best of Luck!

7 0

3 years ago

If ∠1≅∠2, then ___...