1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
melamori03 [73]
2 years ago
8

The mean time required to repair breakdowns of a certain copying machine is 93 minutes. The company which manufactures the machi

nes claims that breakdowns of its new, improved model are easier to fix. To test this claim, sample of 73 breakdowns of the new model were observed, resulting in a mean repair time of 88.8 minutes and a standard deviation of 26.6 minutes. Use significance level α = 0.05. State clearly what are your null and alternative hypothesis, show your work, and state your conclusion.
Mathematics
1 answer:
Sonja [21]2 years ago
5 0

Answer:

t=\frac{88.8-93}{\frac{26.6}{\sqrt{73}}}=-1.349    

p_v =P(t_{(72)}  

If we compare the p value and the significance level given \alpha=0.05 we see that p_v>\alpha so we can conclude that we have enough evidence to fail reject the null hypothesis, and we can't concluce that the true mean is less than 93 min at 5% of signficance.  

Step-by-step explanation:

Data given and notation  

\bar X=88.8 represent the sample mean

s=26.6 represent the sample standard deviation for the sample  

n=73 sample size  

\mu_o =93 represent the value that we want to test

\alpha=0.05 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)  

State the null and alternative hypotheses.  

We need to conduct a hypothesis in order to check if the true mean i lower than 93 min, the system of hypothesis would be:  

Null hypothesis:\mu \geq 93  

Alternative hypothesis:\mu < 93  

If we analyze the size for the sample is > 30 but we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:  

t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}  (1)  

t-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:  

t=\frac{88.8-93}{\frac{26.6}{\sqrt{73}}}=-1.349    

P-value

The first step is calculate the degrees of freedom, on this case:  

df=n-1=73-1=72  

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

p_v =P(t_{(72)}  

Conclusion  

If we compare the p value and the significance level given \alpha=0.05 we see that p_v>\alpha so we can conclude that we have enough evidence to fail reject the null hypothesis, and we can't concluce that the true mean is less than 93 min at 5% of signficance.  

You might be interested in
Help please thank you
Artist 52 [7]

Answer:

uahabsihsb

Step-by-step explanation:

  1. shahabajwnznjsiay
  2. znsbsk
  3. sksisn
7 0
2 years ago
1 point
s2008m [1.1K]

Answer:

i do not know

Step-by-step explanation:

6 0
2 years ago
What is the value of x?
andrey2020 [161]

Answer:

x = 30°.

Step-by-step explanation:

To calculate the value of 'x', we can first derive the value of one of the angles that make up the triangle.

Notice that there is an angle with a measure of 100°. The angle that makes up the angle of the triangle is called a Vertical Angle. Therefore, if the angle in red is 100°, the vertical angle, or the third angle of the triangle, is 100°.

There are two congruent sides to the triangle, as seen by the congruent lines. This means that both of the other two angles must be equal. Find the value of 'x' by:

180 - 100 = 80. Since the value of one angle was 100°, and the angles in a triangle must add up to 180°, you can simply subtract to find the sum of the other two angles.

(x + 10) + (x + 10) = 80

2x + 20 = 80

2x = 60

x = 30°.

7 0
3 years ago
Read 2 more answers
Find the measure of the indicated angle
Margarita [4]

Answer:

the unknown angle is 88°

Step-by-step explanation:

the exterior angle of a triangle is equal to the sum of the opposite interior angles. Therefore, in the tall triangle, 60 + 40 = 100, meaning the bottom left angle in the small triangle is 100-64=36. And b/c angle sum of a triangle is 180°, 180-36-56=88°

6 0
3 years ago
Read 2 more answers
What are the steps to this?
Evgen [1.6K]

Answer:

B=112

Step-by-step explanation:

Angle B is on the same line as angle A(68). They would need to combine for a total of 180 degrees. So 68-180=112

4 0
3 years ago
Read 2 more answers
Other questions:
  • If my grandma put in 100 dollars every month for collage since I was born and I’m 15 and it’s June how much money do I currently
    6·1 answer
  • How can I get Y result?<br>5y+38 = 180
    6·2 answers
  • 350/100 as a decimal and a percent
    13·2 answers
  • What is the measure of each angle
    13·2 answers
  • What is the equivalent decimal to 1/2?
    5·2 answers
  • MATH QUESTION PLEASE HELP!!!
    13·2 answers
  • How many real solutions does x^2+8x+20=0 have?<br> 1. 0<br> 2. 1<br> 3. 2
    8·2 answers
  • Quadrilateral ABCD is a rhombus.<br> AD = 13 cm &amp; BD = 24 cm,<br><br> find AC
    7·1 answer
  • What is the difference between 22,769 and 18,995
    8·2 answers
  • 7) What is the area of the figure below?<br> 12 cm<br> 13 cm<br> 20 cm<br> 21 cm
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!