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
mina [271]
2 years ago
12

The mean waiting time at the drive-through of a fast-food restaurant from the time the food is ordered to when it is received is

85 seconds. A manager devises a new system that he believes will decrease the wait time. He implements the new system and measures the wait time for 10 randomly sampled orders. They are provided below:
109 67 58 76 65 80 96 86 71 72
Assume the population is normally distributed.
(a) Calculate the mean and standard deviation of the wait times for the 10 orders.
(b) Construct a 99% confidence interval for the mean waiting time of the new system.
Mathematics
1 answer:
alexira [117]2 years ago
8 0

Answer:

a) And if we replace we got: \bar X= 78

s = 15.391

b) 78-3.25\frac{15.391}{\sqrt{10}}=62.182    

78-3.25\frac{15.391}{\sqrt{10}}=93.818    

So on this case the 99% confidence interval would be given by (62.182;93.818)    

Step-by-step explanation:

Dataset given: 109 67 58 76 65 80 96 86 71 72

Part a

For this case we can calculate the sample mean with the following formula:

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

And if we replace we got: \bar X= 78

And the deviation is given by:

s =\sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}

And if we replace we got s = 15.391

Part b

The confidence interval for the mean is given by the following formula:

\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}   (1)

In order to calculate the critical value t_{\alpha/2} we need to find first the degrees of freedom, given by:

df=n-1=10-1=9

Since the Confidence is 0.99 or 99%, the value of \alpha=0.01 and \alpha/2 =0.005, and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.005,9)".And we see that t_{\alpha/2}=3.25

Now we have everything in order to replace into formula (1):

78-3.25\frac{15.391}{\sqrt{10}}=62.182    

78-3.25\frac{15.391}{\sqrt{10}}=93.818    

So on this case the 99% confidence interval would be given by (62.182;93.818)    

You might be interested in
What is the range of the cluster in the scatter plot?
mestny [16]
I think that it is C
3 0
3 years ago
Read 2 more answers
George wrote an integer. The opposite of George’s integer is -53. Which of these statements about George’s integer must be true?
vlabodo [156]

The George's integer must be true for option D)I and IV.

What is integer?

 A full number (not a fraction) that can be positive, negative, or zero is called an integer . -5, 1, 5, 8, 97, and 3, 043 are some examples of integers. 1.43, 1 3/4, 3.14, and other numbers are examples of non-integer numbers. Integer, which means full or whole in Latin, is the root of the English term integer. A particular category of numbers called integers includes zero, positive numbers, and negative numbers. All whole numbers, both negative and positive, and 0 are considered integers.

Here the opposite of George integer is -53.

We know that opposite value of x is -x.

Then George integer is 53.

George integer must be true for The given options I. the integer is 53 and IV.The integer has absolute value of 53.

Therefore the correct option is  D) I and IV.

To learn more about integer refer the below link

brainly.com/question/13723636

#SPJ9

5 0
10 months ago
In the diagram what is m
Virty [35]
The diagram for m<VSR is 80°
6 0
3 years ago
Juan is saving money to buy a game. So far he has saved ,$12 which is three-fourths of the total cost of the game. How much does
REY [17]
─── ∙ ~εïз~ ∙ ───
answer: 16

how? 100/4 = 25
3/4 = 0.75 because 25 x 3 = 0.75
0.75x = 12
12/0.75 = 16
3 0
2 years ago
2/3 divided by 1/4<br> HELP ME PLEASEEE
kap26 [50]

Answer: 2 and 2/3

Step-by-step explanation: In this problem, we have 2/3 ÷ 1/4.

Dividing by a fraction is the same as multiplying by its reciprocal. In other words, we can change the divison sign to multiplication and flip the second fraction.

So here, 2/3 ÷ 1/4 can be rewritten as 2/3 × 4/1.

Now we are simply multiplying fractions so we multiply across the numerators or top number number and multiply across the denominators or bottom numbers.

\frac{2}{3} x \frac{4}{1} = \frac{8}{3}  

8/3 can be converted into a mixed number by dividing the denominator of the fraction into the numerator of the fraction.

3 divides into 8 2 with a remainder of 2 times so our whole number will be 2 and our new numerator will be 2 as well. We will put this over our original denominator which is 3. Now we have 2 and 2/3.

4 0
2 years ago
Other questions:
  • Solve the formula for a,the acceleration due to gravity
    13·1 answer
  • Arturo ran 17 laps that were 1/5 mile long. Axel ran 7 laps that were 1/2 mile long. Who ran further, prove it. (5 sentence resp
    12·1 answer
  • A piece of cloth is folded into a square with a side length measuring x inches. When it is unfolded, it has an area of x2 + 27x
    7·2 answers
  • A certain shop repairs both audio and video components. Let A denote the event that the next component brought in for repair is
    11·2 answers
  • In how many ways can 4 people have different birth months?
    12·1 answer
  • Carmen is 153.95 cm tall. Marcus is 160.2 cm tall. Who is taller? By how much?
    14·1 answer
  • Determine the vertex of the function f(x) = 3x2 – 6x + 13.
    14·1 answer
  • please help! 20 points for answering. if you guess or just write something to just get points i will make sure your account gets
    5·1 answer
  • Given right triangle jkl, what is the value of cos(l)? five-thirteenths five-twelfths twelve-thirteenths twelve-fifths
    8·1 answer
  • suppose we want to choose 5 letters, without replacement, from 13 distinct letters. (a) how many ways can this be done, if the o
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!