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
oksano4ka [1.4K]
3 years ago
10

The manager of Petco, a nationwide chain of pet supply stores, wants to study characteristics of the customers, particularly the

amount of money spent by customers and whether the customers own only one dog, only one car, or more than on dog and/or cat. The results from a sample of 70 customers are as follows: Amount of money spent: LaTeX: X-bar\:=\:\text{21.34}X − b a r = 21.34 LaTeX: S\:=\:\text{9.22}S = 9.22 Thirty-seven customers own only a dog. Twenty-six customers own only a cat. Seven customers own more than one dog and/or cat. Construct a 95% confidence interval estimate for the population mean amount spent in the pet supply store.
Mathematics
1 answer:
shutvik [7]3 years ago
3 0

Answer:

The 95% confidence interval would be given by (19.141;23.538)  

Step-by-step explanation:

1) Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

\bar X=21.34 represent the sample mean for the sample  

\mu population mean (variable of interest)

s=9.22 represent the sample standard deviation

n=70 represent the sample size  

2) Confidence interval

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=70-1=69

Since the Confidence is 0.95 or 95%, the value of \alpha=0.05 and \alpha/2 =0.025, and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,69)".And we see that t_{\alpha/2}=1.994

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

21.74-1.994\frac{9.22}{\sqrt{70}}=19.141    

21.74+1.994\frac{9.22}{\sqrt{70}}=23.538

So on this case the 95% confidence interval would be given by (19.141;23.538)    

You might be interested in
PLLLZZ HELP IF U DONT KNOW ANSWER DONT!!!!
Mice21 [21]

Answer:

subtract 22 on both sides

Step-by-step explanation:

hope this helps :)

4 0
3 years ago
Read 2 more answers
shawn has two fields on his farm. he plants two types of corn. each field has 60 rows of cornstalks. type a grows better so ther
WINSTONCH [101]

Type a= 8x60

=480

b=3x60

=180

6 0
3 years ago
Six identically shaped place mats, marked a, b, c, d, e and f, are piled neatly in a stack. how many arrangements are possible i
Sedaia [141]
6
1. A, b, c
2. A, b, d
3. A, b, e
4. C, a, b
5. D, a, b
6. E, a, b

Hope I helped!
5 0
3 years ago
15. What is 3% of 4.14 x 10?
Slav-nsk [51]

Answer:

the answer is a and I hope this helps you.

5 0
1 year ago
Read 2 more answers
The theoretical probability of choosing Event A is 2
Crazy boy [7]

Answer: \dfrac{5}{7}

Step-by-step explanation:

Given

The theoretical probability of choosing an event  A is \dfrac{2}{7}

The sum of the probability of occuring and non-occuring of an event is always equal to 1.

So, the probability of non choosing Event A is

\Rightarrow 1-\dfrac{2}{7}\\\\\Rightarrow \dfrac{7-2}{7}\\\\\Rightarrow \dfrac{5}{7}

8 0
3 years ago
Other questions:
  • Which measurements are the greatest 6kilometers 60 meters 600 centimeters 6000 milimeters
    14·2 answers
  • In the following math problem, which operation should you do FIRST? 8 + 3(72 x 4) – 5 ÷ 2
    12·2 answers
  • Choose all the numbers that 135 is divisible by.<br><br> 2<br> 3<br> 4<br> 5<br> 6<br> 9<br> 10
    12·1 answer
  • The radius of a sphere is increasing at a rate of 3 mm/s. how fast is the volume of the sphere increasing when the diameter is 1
    7·1 answer
  • What the precents and decimals of these fraction 5/8. 66/200. 5 2/5. 2 7/16. has to be simplyed
    15·1 answer
  • ONE PROBLEM PLEASE HELP I DONT GET THIS AT ALL
    10·1 answer
  • The South prospered, but its wealth was very unequally distributed. Upward social mobility did not exist for the millions of sla
    7·1 answer
  • What is the answer to y=-6x-3, -8x-3y=-1.
    11·1 answer
  • Help please!<br> Thank you!!
    6·1 answer
  • What is the explicit formula for this sequence?<br><br> −7, −4, −1, 2, 5, …
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!