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]
3 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]3 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
A model airplane is shot up from a platform 1 foot above the ground with an initial upward velocity of 56 feet per second. The h
Law Incorporation [45]
H=-16t^2+56t+1, the airplane is shot up from a platform 1 foot above the ground, so 1= - 16t^2+56t+1, we solve this equation
(- 16t+56)t=0, (- 16t+56)=0 or t=o, - 16t+56=0, implies t =3.5s
so the answer is C)3.5 seconds 
4 0
3 years ago
Read 2 more answers
A fruit stand sells 6 oranges for $3 and 3 grape fruit for $2.40 .Lionel buys 10 oranges and 11 grapefruits. how much does Lione
Flura [38]
6oragnes=3dollars
divide 6
1oragne=0.5dollar

3grapefruit=2.4dollar
divide3
1grapefruit=0.6dollar

10 oranges and 11 grapefuites
(10 times 0.5)+(11 times 0.6) =
5+6.6=11.6

answer is $11.6
8 0
3 years ago
Read 2 more answers
Help me please!! this is due today​
melisa1 [442]
30 centimeters cubic centimeters
6 0
2 years ago
Describe one error that was made in the preparation of the
pashok25 [27]

Answer:

  the axis labels are inconsistent with the graph title

Step-by-step explanation:

The independent variable is described as "% protein digested", and the dependent variable is described as "time." The graphed values suggest that these are reasonable descriptors for the data being plotted.

The title, however, says the data points are "percentage digestion per hour". This is in disagreement with the axis labels, and is inconsistent with the shape of the curve. (If the title is to be believed, the digestion rate is such that more than 100% of <whatever> has been digested after 10 hours.)

__

<em>Additional comment</em>

Another error is the vertical axis is graduated as though it were linear, but it is decidedly non-linear. Equivalent distances on the graph are shown for differences of 10%, 5%, 10% and 25%. That is the scale varies by a factor of 5 from one part of the graph to another.

8 0
3 years ago
HELP MEEE PLEASE ILL MARK BRIANLIST!!!!
Aleksandr-060686 [28]
The points in order from top to bottom are :

F
E
C
H
I
5 0
3 years ago
Read 2 more answers
Other questions:
  • 12. The geographic grid apportions the globe into hemispheres of 180 lines of longitude. Based on your knowledge of basic geomet
    5·1 answer
  • EXPERTS/ACE PLEASE HELP!!
    12·1 answer
  • jessica's high school played 651 baseball games this year, 118 of the games were played at night. she attended 335 games. how ma
    10·2 answers
  • a submarine dives to a depth of 54.6 meters below the surface of the water in 4 minutes. what integer represents the constant ra
    14·1 answer
  • What is the maximum value of 18.6
    5·1 answer
  • Lauren coordinates a construction projects for a cement company. A government project requires constructing two rectangular conc
    10·1 answer
  • What is the definition of similar figures
    13·1 answer
  • Simplify the following expression: 2(3 + a) + 6(a + 2)
    11·2 answers
  • Value of [(3/2)^(-2)] is *​
    8·1 answer
  • A family eat 1/2/3 breads at a meal . will 3 breads i s enough for 2 meal
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!