Questions
In Norway, the distribution of birth weights for full-term infants whose gestational age is 40 weeks...

In Norway, the distribution of birth weights for full-term infants whose gestational age is 40 weeks is approximately normal with mean μ= 3500 grams. We wish to determine if the birth weights of full-term babies whose mothers smoked throughout pregnancy is less than those of non-smoking mothers. A sample of 17 babies born to mothers who smoked is collected. The sample mean is 3297 grams and the sample standard deviation is 430 grams.

Test your hypothesis at the α = 0.05 level and explain what the results mean.

In: Statistics and Probability

The Transportation Safety Authority (TSA) has developed a new test to detect large amounts of liquid...

The Transportation Safety Authority (TSA) has developed a new test to detect large amounts of liquid in luggage bags. Based on many test runs, the TSA determines that if a bag does contain large amounts of liquid, there is a probability of 0.9 the test will detect it. If a bag does not contain large amounts of liquid, there is a 0.09 probability the test will conclude that it does (a false positive). Suppose that in reality only 1 in 100 bags actually contain large amounts of liquid.

a. What is the probability a randomly selected bag will have a positive test? Give your answer to four decimal places.

b. Given a randomly selected bag has a positive test, what is the probability it actually contains a large amount of liquid? Give your answer to four decimal places.

c. Given a randomly selected bag has a positive test, what is the probability it does not contain a large amount of liquid? Give your answer to four decimal places.

In: Statistics and Probability

A survey of several 11 to 13 year olds recorded the following amounts spent on a...

A survey of several 11 to 13 year olds recorded the following amounts spent on a trip to the mall:

$28.43,$25.23,$23.98,$24.79,$29.05

Construct the 95% confidence interval for the average amount spent by 11 to 13 year olds on a trip to the mall. Assume the population is approximately normal.

Step 3 of 4 : Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.

In: Statistics and Probability

An insurance company has the business objective of reducing the amount of time it takes to...

An insurance company has the business objective of reducing the amount of time it takes to approve applications for life insurance. The approval process consists of underwriting, which includes a review of the application, a medical information bureau check, possible requests for additional medical information and medical exams, and a policy compilation stage in which policy pages are generated and sent for delivery. The ability to deliver the policies to customers in a timely manner is critical to the profitability of the service. During a period of one month, a random sampling of 27 approved policies is selected, and the total processing time, in days, is collected. These data are stored in the table called Insurance.

73 19 16 64 28 28 31 90 60 56 31 56 31 56 22 18 45 48 17 17 17 91 92 63 50 51 69 16 17

A.         In the past, the mean processing time was 45 days. At the 0.05 level of significance, is there evidence that the mean processing time has changed in 45 days?

B.         What assumption about the population distribution is needed to conduct the t-test?

C.         Construct a boxplot or a normal probability plot to evaluate the assumption made in (b).

D. Do you think that the assumption needed in order to conduct the t-test in(a) is valid? Explain.

Use Excel to solve part C

In: Statistics and Probability

In a random sample of six microwave​ ovens, the mean repair cost was ​$75.00 and the...

In a random sample of six microwave​ ovens, the mean repair cost was ​$75.00 and the standard deviation was ​$11.00. Assume the population is normally distributed and use a​ t-distribution to construct a 99​% confidence interval for the population mean μ. What is the margin of error of μ​? Interpret the results.

In: Statistics and Probability

Draw the feature space plot (scatter plot) for the Green-Red, NIR-Green and NIR-Red band combinations. Based...

  1. Draw the feature space plot (scatter plot) for the Green-Red, NIR-Green and NIR-Red band combinations. Based on these plots, which two bands are the most correlated?

    105

    97

    85

    82

    82

    81

    108

    104

    93

    82

    81

    81

    106

    109

    102

    88

    81

    81

    106

    108

    103

    89

    84

    81

    105

    106

    104

    95

    89

    83

    104

    102

    98

    94

    90

    86

    Green

    128

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    95

    89

    89

    90

    129

    124

    109

    94

    89

    89

    128

    133

    125

    102

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    101

    95

    90

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    126

    112

    104

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    128

    125

    118

    108

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    96

    Red

    102

    97

    91

    91

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    92

    104

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    96

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    90

    90

    103

    106

    100

    92

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    93

    92

    89

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    102

    97

    95

    90

    101

    99

    98

    99

    98

    94

    NIR

In: Statistics and Probability

These are a few short answer questions I am stumped on. 1. What is the sampling...

These are a few short answer questions I am stumped on.

1. What is the sampling distribution of the difference between means? Why can’t you conduct an independent samples t-test without it?

2. What are the assumptions of a two-sample t-test?

3. Why do we “pool” variance for a two-sample t-test? What are the assumptions that make this possible? How does it benefit us?

5. Why is a confidence interval not a probability statement?

9. What is an effect size? What happens to an effect size when sample size increases/decreases? Why?

10. What is power? How is it related to the α-level, sample size, and effect size?

In: Statistics and Probability

x (Bins) frequency 0 0 1 0 2 0 3 2 4 5 5 8 6...

x (Bins) frequency
0 0
1 0
2 0
3 2
4 5
5 8
6 13
7 33
8 42
9 66
10 77
11 105
12 103
13 110
14 105
15 84
16 70
17 51
18 40
19 27
20 27
21 15
22 5
23 7
24 2
25 2
26 1
27 0
28 0
29 0
30 0

(7) On the Histogram worksheet, calculate all frequencies of the distribution using the table shown. (To three decimal places) The relative frequency of all values in the (X ≤ 7) range is ______.

(8) On the Histogram worksheet, calculate all frequencies of the distribution using the table shown. (To three decimal places) The relative frequency of all values in the (9 ≤ X ≤ 18) range is ______.

(9) On the Histogram worksheet, calculate all frequencies of the distribution using the table shown. (To three decimal places) The relative frequency of all values in the (X ≥ 15) range is ______.

(10) On the Histogram worksheet, calculate all frequencies of the distribution using the table shown. (To three decimal places) The relative frequency of all values in the (12 ≤ X < 20) range is ______.

In: Statistics and Probability

The income distribution in two cities is the following City A City B 10000 – 12000...

The income distribution in two cities is the following

City A

City B

10000 – 12000

10000

5000 – 7000

4000

12000 - 14000

5000

7000 – 9000

6000

14000 - 16000

20000

9000 – 11000

8000

16000 – 18000

50000

11000 – 13000

14000

18000 - 20000

40000

13000 – 15000

16000

20000- 22000

2000

15000 - 17000

2000

Find the standard deviation and the coefficient of Variation for each company and comment on the results.

In: Statistics and Probability

In a recent survey of 150 students at a large community college, 86 students said they...

In a recent survey of 150 students at a large community college, 86 students said they were “regular” coffee drinkers. It is known that 64% of all students at that community college are “regular” coffee drinkers. Use this information to compute necessary quantities, and fill in the blanks: The average distance between the values of the sample proportion (from all possible random samples of 150 students from this community college) of "regular" coffee drinkers and the population proportion 0.64 of "regular" coffee drinkers in this community college is approximately_________. We estimate that the values of the sample proportion (from all possible random samples of 150 students from this community college) of "regular" coffee drinkers vary from the population proportion of "regular" coffee drinkers in this community college of 0.64 by about _________ , on average.

In: Statistics and Probability

When would a Parole Officer want to know the mean differences between two or more groups?...

When would a Parole Officer want to know the mean differences between two or more groups? Describe a situation, including why and how it would be used.

In: Statistics and Probability

Total plasma volume is important in determining the required plasma component in blood replacement therapy for...

Total plasma volume is important in determining the required plasma component in blood replacement therapy for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that a random sample of 46 male firefighters are tested and that they have a plasma volume sample mean of x = 37.5 ml/kg (milliliters plasma per kilogram body weight). Assume that σ = 7.50 ml/kg for the distribution of blood plasma. (a) Find a 99% confidence interval for the population mean blood plasma volume in male firefighters. What is the margin of error? (Round your answers to two decimal places.) lower limit upper limit margin of error (b) What conditions are necessary for your calculations? (Select all that apply.) the distribution of weights is normal the distribution of weights is uniform σ is unknown n is large σ is known (c) Interpret your results in the context of this problem. 1% of the intervals created using this method will contain the true average blood plasma volume in male firefighters. The probability that this interval contains the true average blood plasma volume in male firefighters is 0.01. 99% of the intervals created using this method will contain the true average blood plasma volume in male firefighters. The probability that this interval contains the true average blood plasma volume in male firefighters is 0.99. (d) Find the sample size necessary for a 99% confidence level with maximal margin of error E = 2.80 for the mean plasma volume in male firefighters. (Round up to the nearest whole number.) male firefighters

In: Statistics and Probability

According to Readers Digest, 49% of primary care doctors think their patients receive unnecessary medical care....

According to Readers Digest, 49% of primary care doctors think their patients receive unnecessary medical care. Use z-table.

a. Suppose a sample of 290 primary care doctors was taken. Show the sampling distribution of the proportion of the doctors who think their patients receive unnecessary medical care.

E(p)=

O(p)=

b. What is the probability that the sample proportion will be within (plus/minus) 0.03 of the population proportion. Round your answer to four decimals.

c. what is the probability that the sample poportion will be within (plus/minus) 0.05 of the population proportion. Round your answer to four decimals.

In: Statistics and Probability

Consider the following sample data for the relationship between advertising budget and sales for Product A:...

Consider the following sample data for the relationship between advertising budget and sales for Product A: Observation 1 2 3 4 5 6 7 8 9 10 Advertising ($) 40,000 50,000 50,000 60,000 70,000 70,000 80,000 80,000 90,000 100,000 Sales ($) 240,000 308,000 315,000 358,000 425,000 440,000 499,000 494,000 536,000 604,000 What is the predicted sales quantity for an advertising budget of $68,000? Please round your answer to the nearest integer. Note that the correct answer will be evaluated based on the full-precision result you would obtain using Excel.

In: Statistics and Probability

Suppose we have annual income for a sample of men and women provided below. Either using...

Suppose we have annual income for a sample of men and women provided below. Either using Excel or conducting this by hand, test to see whether the average annual income of men and women are the same. Conduct this at the 0.05 level. Make sure to test (also at the 0.05 level) that variances are the same. Show all your work or provide Excel output with a written explanation.

    Men

Women

99000

47000

32500

46500

14500

47200

78000

46900

22000

47300

15000

47250

92000

46750

11000

47100

37000

67000

In: Statistics and Probability