1A) The proportions of defective parts produced by two machines were compared, and the following data were collected. Determine a 90% confidence interval for p₁ - p₂. (Give your answers correct to three decimal places.)

Lower Limit -

Upper Limit -

1B) Find the value of t for the difference between two means based on an assumption of normality and this information about two samples. (Use sample 1 - sample 2. Give your answer correct to two decimal places.)

Use the following pairs of observations to construct an​ 80% and a​ 98% confidence interval for  β1.

The​ 80% confidence interval is (______) ​(Round to two decimal places as​ needed.)

The​ 98% confidence interval is (______) ​(Round to two decimal places as​ needed.)

Many standard statistical methods that you will study in Part II of this book are intended for use with distributions that are symmetric and have no outliers. These methods start with the mean and standard deviation, x and s. For example, standard methods would typically be used for the IQ and GPA data here data215.dat.

(a) Find x and s for the IQ data. (Round your answers to two decimal places.)

X=

s=

Here are the numbers

obs     gpa     iq      gender  concept
1       9.88    81      2       67
2       10.7    114     2       43
3       7.08    128     2       52
4       4.09    112     2       66
5       8.8     107     1       58
6       7.7     86      2       51
7       7.19    107     2       71
8       4.97    86      2       51
9       9.82    91      1       49
10      8.26    81      2       51
11      9.92    100     1       35
12      9.34    105     1       54
13      8.23    94      2       54
14      6.57    76      1       64
15      10.29   117     1       56
16      10.65   116     1       69
17      2.26    113     1       55
18      7.65    122     1       65
19      6.4     102     2       40
20      10.66   111     1       66
21      8.18    120     2       55
22      10.54   80      2       20
24      5.83    112     1       56
26      10.07   94      2       68
27      10.39   130     1       69
28      5.25    103     2       70
29      10.38   77      2       80
30      9.23    112     2       53
31      5.69    77      2       65
32      8.61    103     1       67
33      10.58   82      1       62
34      8.21    108     1       39
35      8.77    101     2       71
36      5.21    101     2       59
37      9.68    101     1       60
38      5.58    128     2       64
39      10.25   98      2       71
40      4.08    110     1       72
41      10.64   84      1       54
43      6.6     120     2       64
44      8.78    101     2       58
45      8.72    80      2       70
46      8.64    106     2       72
47      10.19   75      2       70
48      7.04    97      2       47
50      8.58    109     2       52
51      8.33    102     1       46
52      10.81   77      2       66
53      6.87    128     2       67
54      10.86   89      2       63
55      7.08    94      2       53
56      8.1     126     2       67
57      5.55    111     2       61
58      7.31    124     1       54
59      1.29    96      1       60
60      8.86    110     1       60
61      8.78    106     2       63
62      9.63    112     2       30
63      6.75    100     2       54
64      7.77    108     2       66
65      6.36    96      2       44
68      6.47    99      2       49
69      10.77   90      1       44
71      7.97    100     2       67
72      9.64    118     1       64
74      5.79    108     2       73
76      9.06    117     2       59
77      7.93    112     1       37
78      9.64    87      1       63
79      8       94      2       36
80      10.29   92      1       64
83      5.28    107     2       42
84      9.24    86      1       28
85      7.7     120     1       60
86      6.57    108     1       70
87      9.68    96      2       51
88      7.21    74      1       21
89      3.94    95      2       56

1. The human resources manager at Humber Electronics is interested in relating an employee’s score on a job satisfaction questionnaire to his or her length of service, hourly wage rate, and workload. She defined the variables as follows:
   
   x₁ = number of years with company
   
   x₂ = number of years in current position
   
   x₃ = annual salary (in thousands of dollars)
   
   x₄ = workload (number of hours worked per week)
   
   y = job satisfaction score (out of 15)
   
   The HR manager randomly selected relevant information (see below) about 30 employees. Using Excel, obtain the regression output for the data and answer the following questions:
   1. Explain the meaning of the b₃ coefficient as it relates to this data. [5 point]
      
   2. Calculate the coefficient of determination ( R² ) (4 decimal places). Explain the meaning as it relates to this data. [10 point]
      
   3. State the values of the adjusted coefficient of determination and the standard error of estimate (4 decimals). [5 point]
      
   4. Estimate the job satisfaction score for an employee with 10 years with the company, 4 years in the same position, who is paid $35,450 annually and works 35 hours per week . [5 point]

Consider the following data for two independent random samples taken from two normal populations.

(a)

Compute the two sample means.

Sample 1Sample 2

(b)

Compute the two sample standard deviations. (Round your answers to two decimal places.)

Sample 1Sample 2

(c)

What is the point estimate of the difference between the two population means? (Use Sample 1 − Sample 2.)

(d)

What is the 90% confidence interval estimate of the difference between the two population means? (Use Sample 1 − Sample 2. Round your answers to two decimal places.)

to

A beam that weighs 200 N is connected to a wall by a hinge so that it makes an angle of θ = 30.0◦ with the horizontal. The beam is 1.50 m long and is held in place by a cable that runs horizontally from the end of the beam to the wall. A box that weighs 100 N hangs from the end of the beam. Calculate a) the tension in the cable connected to the wall and b) the magnitude and direction of the force exerted by the hinge on the beam.

An 85.4-kg climber is scaling the vertical wall of a mountain. His safety rope is made of nylon that, when stretched, behaves like a spring with a spring constant of 1.19 103 N/m. He accidentally slips and falls freely for 0.815 m before the rope runs out of slack. How much is the rope stretched when it breaks his fall and momentarily brings him to rest?

Table exploring the relationship between exposure to IPV (IPV exposure) durantion of IPV (IPV duration), family relationships (M=Mother, F=Father, C=child), anxiety, depression, post traumatic stress, and dissociation. Below is a correlation matrix based on findings. Please make some statements about significant and insignificant findings.

Variables                   1.            2.        3      4.    5.         6.      7.        8     9.      10.     11     12.

1. IPV Exposure

2. IPV Duration      −.38**

Perceptions of family relationships

3. F-M cohesion TS −.59** .18 7

4. F-C cohesion TS −.40** .15 .70**

5. M-C cohesion TS −.25 .22 .30** .00

6. F-M cohesion CS −.46** .06   .52**    .26 .   26

7. F-C cohesion CS −.46** .07   .49** .61** −.00    −.52**

8. M-C cohesion CS −.23     .06    .18       -.13       .52** .24   −.17

Symptoms of post-traumatic stress disorder

9. Anxiety                  .03* −.48** −.36* −.30*   −.02 −.20   −.20    −.23

10. Depression         .22   −.38**   −.22   −.26   .10   −.05   −.15   −.08 .69**

11. Anger                    .23    −.26     −.12    −.20   .05   −.12 −.02   .02    .26    .44**

12. Post-traumatic    .23    −.22     −.36* −.35* .02 −.12   −.16 −.03 .75** .70** .32*

13. Dissociation        .11    −.06    −.08      −.26    .22    −.18   −.27    .00    .56** .67** .50** .71**

* p < .05 ** p < .0

A manufacturing company manufactures 100 products every day. There is a 5% chance that any of the manufactured products is defective and the products are independent. Consider the 100 products manufactured on a single day.

Find the probability that

(a) only the first and the last products are defective and the rest are good

(b) no more than 2 products are defective

(c) the third defective product happens to be the 60th product

(d) there are two defective products within the first 50 products and two more defective products within the second set of 50 products.

Periodic Inventory Using FIFO, LIFO, and Weighted Average Cost Methods

The units of an item available for sale during the year were as follows:

There are 20 units of the item in the physical inventory at December 31. The periodic inventory system is used. Determine the inventory cost using (a) the first-in, first-out (FIFO) method; (b) the last-in, first-out (LIFO) method; and (c) the weighted average cost method (round per unit cost to two decimal places and your final answer to the nearest whole dollar).