The overhead reach distances of adult females are normally distributed with a mean of

205.5 cm

and a standard deviation of

8.6 cm

a. Find the probability that an individual distance is greater than

214.80cm.

b. Find the probability that the mean for

25

randomly selected distances is greater than 204.00 cm.

c. Why can the normal distribution be used in part​ (b), even though the sample size does not exceed​ 30?

A researcher would like to determine whether an over-the-counter herbal nasal spray has an effect on mental alertness for infants. A sample of n = 16 infants is obtained, and each baby is given a standard dose of the spray one hour before being tested for mental alertness. For the general population of infants, scores on a mental alertness screening test are normally distributed with μ = 60. The infants in the sample had an average score of M = 56.5 and an s = 8.

Can the researcher conclude that scores on the screening test are significantly different after administering the spray? Use a two-tailed test with α = .05. Be sure to state your null hypothesis, a decision about that null hypothesis, and a conclusion explaining your results with an APA format statement. Calculate Cohen’s d if necessary.

the college bookstore says that the average cost of textbooks is $52 with a standard deviation of $4.50. a group of skeptical statistics students want to test the bookstore’s claim with a sample of 100 books, and find a mean of $53. a) what decision should the students make if they set alpha to .01?

b.) Compare and contrast the benefits and drawbacks of having a high alpha level vs. a low alpha level. What are some of the practical/real world implications of either setting an alpha level too high (i.e., .1) or too low (i.e., .001) in your study/analysis?

The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and female consumers differ in the amounts they spend? The average expenditure in a sample survey of 40 male consumers was $135.67, and the average expenditure in a sample survey of 35 female consumers was $68.64. Based on past surveys, the standard deviation for male consumers is assumed to be $39, and the standard deviation for female consumers is assumed to be $20.

1. What is the point estimate of the difference between the population mean expenditure for males and the population mean expenditure for females (to 2 decimals)?
2. At 99% confidence, what is the margin of error (to 2 decimals)?
3. Develop a 99% confidence interval for the difference between the two population means (to 2 decimals). Use z-table.
   (  ,  )

A small hair salon in Denver, Colorado, averages about 50 customers on weekdays with a standard deviation of 8. It is safe to assume that the underlying distribution is normal. In an attempt to increase the number of weekday customers, the manager offers a $2 discount on 5 consecutive weekdays. She reports that her strategy has worked since the sample mean of customers during this 5 weekday period jumps to 57. [You may find it useful to reference the z table.]

a. What is the probability to get a sample average of 57 or more customers if the manager had not offered the discount? (Round “z” value to 2 decimal places, and final answer to 4 decimal places.)

It is known that 5% of the radio tubes produced by a certain manufacturer are defective. If the manufacturer sends out lots containing 100 tubes, what is the probability that at least 98% of the

tubes are good?

1. Flu cases this past flu season in the Remulak school system (n = 500) were 15 per week. For the entire state, the weekly average was 16, and the standard deviation was 15.1. Are the kids in Remulak as sick as the kids throughout the state?
2. The night-shift workers in three of Super Bo's specialty stores stock about 500 products in about 3 hours. How does this rate compare with the stocking done in the other 97 stores in the chain, which average about 496 products stocked in 3 hours? Are the stockers at the specialty stores doing a “better than average” job? Here's the info that you need:

PLEASE ANSWER THE THREE QUESTION WITH CORRCT DEATILAS

Who may request a copy of a birth and death certificate?

If the mother is not married, can the father’s name be placed on the birth certificate?

What does father need to sign in order to be placed on birth certificate of unwed mother?

The cost of adding a new communication node at a location not currently included in the network is of concern to a major manufacturing company. To try to predict the price of new communication nodes, data were obtain on a random sample of existing nodes.

We have information on the following variables:

?: Installation cost of the node, in U.S. dollars (COST)

?1: Number of ports available for access (NUMPORTS)

?2: Bandwidth (BANDWIDTH)

?3: Port speed (PORTSPEED)

Use MINITAB to answer the following questions.

COST NUMPORTS BANDWIDTH PORTSPEED
52388 68 58 653
51761 52 179 499
50221 44 123 422
36095 32 38 307
27500 16 29 154
57088 56   141 538
54475 56 141 538
33969 28 48 269
31309 24 29 230
23444 24 10 230
24269 12 56 115
53479 52 131 499
33543 20 38 192
33056 24 29 230

Perform a global F-test by completing the following steps:

a. The null hypothesis is ?0: ?1 = ?2 = ?3 = 0, what is the alternative hypothesis?

b. What is the p-value for this test?

c. Is there evidence that at least one explanatory variable (number of ports, bandwidth, or port speed) is useful in explaining the variation in the installation cost for communication nodes? (Circle one) i. Yes ii. No

d. What is the value of the MSE for the full model?

Consider the experiment of rolling two dice (six sides each dice). Consider the

following events:

A = the sum is less than or equal to four

B = the sum is a prime number greater than five

C = the sum is greater than or equal to nine

D = the sum is an even number

Determine:

1) P (A or B)

2) P (B and C)

3)P (D / C)

1. What is the statistic and its formula to address this research question? [1pt]

3. Fill in the blanks in the table. [2 pt]

4. Calculate the t-value? [2 pt]

5. What is the critical value if alpha = 0.05 for two-tailed test? [2 pt]

6. Do we reject or accept the hypothesis?

7. What is the effect size (Cohen’s d)?

Data A: Students’ Spatial Ability

The International Air Transport Association surveys business travelers to develop quality ratings for transatlantic gateway airports. The maximum possible rating is 10. Suppose a simple random sample of 50 business travelers is selected and each traveler is asked to provide a rating for the Miami International Airport. The ratings obtained from the sample of 50 business travelers follow.

Develop a 95% confidence interval estimate of the population mean rating for Miami. (Round your answers to two decimal places.)

You may need to use the appropriate technology to answer this question.

Consider the following hypothesis test.

H₀: μ₁ − μ₂ = 0

H_a: μ₁ − μ₂ ≠ 0

The following results are from independent samples taken from two populations.

(b) What is the degrees of freedom for the t distribution? (Round your answer down to the nearest integer.)

(c) What is the p-value? (Round your answer to four decimal places.)

For this question, please provide each of the five-step hypothesis testing process:

1. State the null and alternative hypothesis
2. Choose the appropriate test statistic
3. Establish the Decision rule (reject if….)
4. Calculate the observed test statistic
5. Make a decision with respect to the hypotheses and then the business implication

Are salaries for Registered Marketing Associates in Jacksonville, Florida lower than those in Houston, Texas? Previous salary data show registered Marketing Associates in Jacksonville earned less than Houston. Suppose a follow-up study of 40 registered marketing associates in Jacksonville and 50 registered marking associates in Houston produced the following results:

Jacksonville: n=40, x-bar=56,100, s=6,000

Houston: n=50, x-bar = 59,400, s=7,000

Assume a level of significance of .05, and formulate the hypothesis so that, if the null hypothesis is rejected, we can conclude that salaries for registered marketing associates are significantly lower in Jacksonville than Houston. Provide the 5 step hypothesis process.

What should you do, as an HR Manager, to increase your recurring efforts in Jacksonville as a result of your survey?

Refer to the accompanying data set and construct a 95​% confidence interval estimate of the mean pulse rate of adult​ females; then do the same for adult males. Compare the results.

Construct a 95​% confidence interval of the mean pulse rate for adult females.

Males
86
71
52
60
54
64
53
76
51
59
73
60
63
76
80
63
65
97
40
89
74
63
73
70
52
65
57
81
72
66
63
97
56
64
57
59
68
69
86
60

Females
79
96
55
69
53
82
76
85
89
56
38
64
86
79
78
64
66
77
62
66
81
84
72
76
88
89
90
87
91
94
71
90
82
81
74
55
97
72
74
74