Question
Asked Mar 9, 2019
15 views
As part of an effort to develop new battery technologies, constant-use life spans of twenty cell phone
batteries were measured (below in hours). Use these values to address
4.
the following question
15.7. 14.6. 15.6. 14.5. 15.2. 16.0. 15.0. 15.7. 16.2. 14.7,
15.3. 16.0, 14.4, 16.2, 16.2. 14.9, 14.8.
15.7, 15.3, 14.6
a.
b,
c.
Do the data appear to be consistent with a normal distribution?
what is the 95% CI on the mean?
What is the 95% CI on the variance?
help_outline

Image Transcriptionclose

As part of an effort to develop new battery technologies, constant-use life spans of twenty cell phone batteries were measured (below in hours). Use these values to address 4. the following question 15.7. 14.6. 15.6. 14.5. 15.2. 16.0. 15.0. 15.7. 16.2. 14.7, 15.3. 16.0, 14.4, 16.2, 16.2. 14.9, 14.8. 15.7, 15.3, 14.6 a. b, c. Do the data appear to be consistent with a normal distribution? what is the 95% CI on the mean? What is the 95% CI on the variance?

fullscreen
check_circle

Expert Answer

Step 1

a.

Check whether the given data appear to be consistent with normal distribution or not:

The data represents the constant use life spans for a random sample of 20 cell phone batteries.

The conditions that describe the consistency of a dataset with normal distribution using the normal probability plot are given below:

  • The data points should form an approximate straight line. Departure of data points from straight line indicates departure from normality.
  • The plot should not show any outliers.

Here, normal probability plot is constructed using the MINITAB software.

Software Procedure:

Step-by-step procedure to draw the normal probability plot using the MINITAB software:

  • Choose Graph > Probability plot.
  • Select Simple, and then click OK.
  • In Graph variables, enter the column of life spans.
  • Click

Output of histogram for the sample dataset of life spans is obtained from the MINITAB software is given below:

fullscreen
Step 2

Comment on the consistent of the data with normal distribution.

From the normal probability plot it is observed that the data points fall near the straight line. This implies that the dataset is approximately normally distributed.

Since, none of the points are far away from the remaining data points. The data does not show any outliers.

Thus, all the conditions are also satisfied.

Hence, it can be concluded that the data appear to be consistent with normal distribution.

Step 3

b.

Construct the 95% confidence interval for the mean life span of cell phone batteries:

Denote the population mean life span of cell phone batteries as μ

Here, 95% confidence interval for the mean life span of cell phone batteries is obtained using MINITAB software.

Software Procedure:

Step by step procedure to obtain the 95% confidence interval to estimate mean life span of cell phone batteries using the MINITAB software:

  • Choose Stat > Basic Statistics > 1 sample t.
  • Choose one or more samples in a column.
  • Enter the column of life spans.
  • C...
fullscreen

Want to see the full answer?

See Solution

Check out a sample Q&A here.

Want to see this answer and more?

Solutions are written by subject experts who are available 24/7. Questions are typically answered within 1 hour.*

See Solution
*Response times may vary by subject and question.
Tagged in

Related Statistics Q&A

Find answers to questions asked by student like you
Show more Q&A
add
question_answer

Q: In a study of 420,077 cell phone users, 107 subjects developed cancer of the brain or nervous system...

A: Given hypothesis test let p be the proportion of cellphone users develop cancer or brain or nervous ...

question_answer

Q: A random sample of 30 binomial trials resulted in 12 success. Test the claim that the population por...

A:  Hi, since the problem posted by you contains multiple sub-parts, we are answering the first three s...

question_answer

Q: Repeat the following procedure for the four given numbers.Multiply the number by 4. Add 4 to product...

A: The first number is 1Step-1 Multiplying by 4 we get =1*4 = 4Step-2 Add 4 to the product we get = 4+4...

question_answer

Q: Number 15 A B C D

A: Note:Thank you for the question. However, your question has more than 3 parts. We are solving first ...

question_answer

Q: A population has a mean of 15 and standard deviation of 3. Round the answers to two decimal places a...

A: Let X be the observation. X follows normal distribution with mean μ = 15 and the standard deviation ...

question_answer

Q: given that the sample mean=105, pop standard deviation=27, n=44, a=0.01 what is the critical s-score

A: Note: In this question it has mentioned that we have to find the s – score but it seems that it is a...

question_answer

Q: yai ayu, au uiaı uie iwu aapico aI IIupcInuc J pi IaIuvII apico ocicLICu 1VIITIVILIany uiouIvulcu pu...

A: Solution:Null and alternative hypotheses:The null and alternative hypotheses to test is given below:...

question_answer

Q: Let x be per capita income in thousands of dollars. Let y be the number of medical doctors per 10,00...

A: Hi, since the problem posted by you contains multiple sub-parts, we are answering the first three su...

question_answer

Q: The book states the following: "The smaller our sample size and the more extreme the outlier score i...

A: We know from equation 1 below that the width of confidence interval is inversely proportional to the...