Questions
In August 2003, 56% of employed adults in the United States reported that basic mathematical skills...

In August 2003, 56% of employed adults in the United States reported that basic mathematical skills were critical or very important to their job. The supervisor of the job placement office at a 4-year college thinks this percentage has increased due to increased use of technology in the workplace. He takes a random sample of 530 employed adults and finds that 324 of them feel that basic mathematical skills are critical or very important to their job. Is there sufficient evidence to conclude that the proportion of employed adults who feel basic mathematical skills are critical or very important to their job has increased at the α = 0.01 level of significance?

The sample proportion is p^ =______- . (Round to 3 decimal places.)
The test statistic for this test is z0=_______.  (Calculate this value in a single step in your calculator using the rounded sample proportion reported above, and report your answer rounded to 3 decimal places.)

We  (reject / fail to reject) H0.
The given data  (does / does not) provide significant evidence that the proportion of employed adults who feel that basic mathematical skills are critical or very important to their job has increased since August 2003.

In: Math

A supermarket chain analyzed data on sales of a particular brand of snack cracker at 104...

A supermarket chain analyzed data on sales of a particular brand of snack cracker

at 104 stores for a certain one week period. The analyst decided to build a regresion model to predict the sales of the snack cracker based on the total sales of all brands in the snack cracker category.

d. Make a prediction for sales in a week where sales in the entire snack

    cracker category is 1005.

CategorySales Sales
1348 394
1110 388
1096 357
1208 385
1063 346
1097 326
1277 358
1275 359
1328 360
1281 374
1127 362
1339 406
1055 354
1263 368
1158 391
1286 370
1401 372
1085 381
1178 371
1248 353
1241 372
1320 375
1353 369
1173 353
1208 364
1280 371
1214 391
1213 381
1291 371
1230 335
1095 338
1149 320
1305 370
1134 351
1127 328
1053 295
1107 318
1054 296
1141 327
1190 313
1071 346
1147 361
1127 350
1204 367
1301 411
1184 390
1214 367
1132 341
1213 380
1173 347
1226 365
1261 352
1118 341
1096 321
1211 329
1033 336
1228 361
1241 386
1381 408
1332 359
1253 375
1043 330
1456 341
1099 340
1044 336
1230 341
1143 371
1238 378
1357 371
1150 378
1218 386
1215 357
1238 376
1196 349
1193 364
1282 361
1317 365
1157 346
1294 356
1198 343
1436 358
1278 368
1124 312
1116 315
1109 338
1285 327
1189 309
1197 330
1091 345
1251 344
1124 355
1130 346
1067 328
1150 352
1238 375
1409 370
1264 377
1151 340
1206 350
1297 375
1164 364
1108 370
1187 365
1459 396

In: Math

Appraise what new statistical methods are used in the evaluation of conceptual theories outlining specific advantages...

Appraise what new statistical methods are used in the evaluation of conceptual theories outlining specific advantages these methods provide. Compare Structural Equation Modeling (SEM) techniques providing advantages of using SEM to other conventional methods outlining some of the various statistical techniques that SEM is able to perform. Evaluate sampling techniques used to conduct hypothetical studies and asses the benefits of each sampling method based on best fit to application. Critique validity and reliability methods for appropriate constructs and compare advantages and disadvantages of each method describing what methods to use with different operational techniques. Compare and evaluate factor analysis for confirmatory versus exploratory methods and assess when each is appropriate proving examples and application usages. Assess the differences of various regression analysis methods and demonstrate by examples what regression methods are most appropriate for different application. Finally discuss and recommend best statistical techniques and methods to operationally use for means comparisons, non parametric evaluation, bivariate correlation, ANOVAs, Chi Square, regression, and other techniques as appropriate. Assess the overall concept of statistical power, why it has import to statistical evaluations, and what SPSS contributes to statistical analysis in today’s research.

In: Math

A supermarket chain analyzed data on sales of a particular brand of snack cracker at 104...

A supermarket chain analyzed data on sales of a particular brand of snack cracker

at 104 stores for a certain one week period. The analyst decided to build a regresion model to predict the sales of the snack cracker based on the total sales of all brands in the snack cracker category.

b. Is there sufficient evidence at 2.5% significance level to claim that linear

    relationship exists between category sales and cracker sales? Show the

   test, and make the conclusion.

CategorySales Sales
1348 394
1110 388
1096 357
1208 385
1063 346
1097 326
1277 358
1275 359
1328 360
1281 374
1127 362
1339 406
1055 354
1263 368
1158 391
1286 370
1401 372
1085 381
1178 371
1248 353
1241 372
1320 375
1353 369
1173 353
1208 364
1280 371
1214 391
1213 381
1291 371
1230 335
1095 338
1149 320
1305 370
1134 351
1127 328
1053 295
1107 318
1054 296
1141 327
1190 313
1071 346
1147 361
1127 350
1204 367
1301 411
1184 390
1214 367
1132 341
1213 380
1173 347
1226 365
1261 352
1118 341
1096 321
1211 329
1033 336
1228 361
1241 386
1381 408
1332 359
1253 375
1043 330
1456 341
1099 340
1044 336
1230 341
1143 371
1238 378
1357 371
1150 378
1218 386
1215 357
1238 376
1196 349
1193 364
1282 361
1317 365
1157 346
1294 356
1198 343
1436 358
1278 368
1124 312
1116 315
1109 338
1285 327
1189 309
1197 330
1091 345
1251 344
1124 355
1130 346
1067 328
1150 352
1238 375
1409 370
1264 377
1151 340
1206 350
1297 375
1164 364
1108 370
1187 365
1459 396

In: Math

Which probability rule would be used to determine the probability of getting into both your first...

Which probability rule would be used to determine the probability of getting into both your first choice graduate program AND getting an interview at your first choice post-graduation?

Solve for the probability of BOTH events occuring if the probability of getting into your first choice graduate program is estimated to be 25% and getting an interview at your first choice job post-graduation is estimated to be 50%.

If the robt = 0.20 and the df = 70 and the test was two-tailed, what is the rcv ?

Given the values provided in #17, should you reject or fail to reject the null hypothesis?

Significance level is 0.05

In: Math

Choose the correct answer. 1. What is the percentile rank of 60 in the distribution of...

Choose the correct answer.

1. What is the percentile rank of 60 in the distribution of N(60, 100)?

a. 10

b. 50

c. 60

d. 100

  1. The skewness value for a set of data is +2.75. This indicates that the distribution of scores is which one of the following?

    1. Highly negatively skewed

    2. Slightly negatively skewed

    3. Symmetrical

    4. Slightly positively skewed

    5. Highly negatively skewed

  2. For a normal distribution, all percentiles above the 50th must yield positive z-scores. Is this true or false?

  3. The distribution of variable X has a mean of 10 and is positively skewed. The distribution of variable Y has the same mean of 10 and is negatively skewed. Are the medians for the two variables the same or different?

In: Math

A starting lineup in basketball consists of two guards, two forwards, and a center. (a) A...

A starting lineup in basketball consists of two guards, two forwards, and a center. (a) A certain college team has on its roster four centers, four guards, three forwards, and one individual (X) who can play either guard or forward. How many different starting lineups can be created? [Hint: Consider lineups without X, then lineups with X as guard, then lineups with X as forward.]

In: Math

(Hypothetical) In a major national survey of crime victimization, the researchers found that 17.0% of Americans...

(Hypothetical) In a major national survey of crime victimization, the researchers found that 17.0% of Americans age 12 or older had been a victim of crime. The size of the sample was 6,4,00.

a) Estimate the percentage of Americans age 12 or older who were victims at the 95% confidence level. Write a sentence explaining the meaning of this confidence interval.

b) Estimate the percentage of victims at the 99% confidence level. Write a sentence explaining the meaning of this confidence interval.

Imagine that the Sample size was cut in half to 3,200, but the survey found the same value of 17.0% for the percentage of victims.

c) Would the 95% confidence interval increase or decrease? By how much?

d) Would the 99% confidence interval increase or decrease? By how much?

In: Math

The number of chocolate chips in a bag of chocolate chip cookies is approximately normally distributed...

The number of chocolate chips in a bag of chocolate chip cookies is approximately normally distributed with a mean of 1262 chips and a standard deviation of 118 chips.

​(a) Determine the 27th percentile for the number of chocolate chips in a bag. ​

(b) Determine the number of chocolate chips in a bag that make up the middle 98​% of bags. ​

(c) What is the interquartile range of the number of chocolate chips in a bag of chocolate chip​ cookies?

In: Math

The effectiveness of antidepressants in treating the eating disorder bulimia was examined in the article “Bulimia...

The effectiveness of antidepressants in treating the eating disorder bulimia was examined in the article “Bulimia Treated with Imipramine: A Placebo-Controlled Double-Blind Study” (American Journal of Psychology [1983]: 554–558). A group of patients diagnosed with bulimia were randomly assigned to one of two treatment groups, one receiving imipramine and the other a placebo. One of the variables recorded was binge frequency. The authors chose to analyze the data using a rank-sum test because it makes no assumption of normality. They stated that “because of the wide range of some measures, such as frequency of binges, the rank sum is more appropriate and somewhat more conservative.” Data on number of binges during one week that are consistent with the findings of the article are given in the following table:

Placebo 8 3 15 3 4 10 6 4

Imipramine 2 1 2 7 3 12 1 5

Do these data strongly suggest that imipramine is effective in reducing the mean number of binges per week? Use a level .05 rank-sum test.

In: Math

There is one 1$ bill and one 5$ bill in your left pocket and three 1$...

There is one 1$ bill and one 5$ bill in your left pocket and three 1$ bills in your right pocket. You move one bill from the left pocket to the right pocket. After that you take one the remaining bill from the left pocket and one of the bills at random from your right pocket. Let ? denote the amount of money that you take from the left pocket and ? denote the amount of money that you take from the right pocket.

1. ? (?=1, ? =1) is

(a) 1

(b) 3 (correct)

(c) 1

(d) 5

2. ? (?=5, ? =5) is

(a) 0 (correct)

(b) 1/8

(c) 3/8

(d) 1/2

3. ?(? ≥?)is
(a) 1/8

(b) 3/8

(c) 1/2 (correct)

(d) 1

4. Covariance between ? and ? is

(a) 0

(b) −1/2

(c) −1 (correct)

(d) 1


5. Let ? denote the total amount of money that you get from your pockets. V??(?) is

(a) 23/4

(b) 31/8

(c) 19/4

(d) 15/4 (correct)

6. Let ? denote the share of money that you get from the left pocket, i.e. ?/? . Calculate the mean of ?
(a) 1/2

(b) 2/3

(c) 11/13

(d) 5/8 (correct)

In: Math

An academic department has just completed voting by secret ballot for a department head. The ballot...

An academic department has just completed voting by secret ballot for a department head. The ballot box contains four slips with votes for candidate A and three slips with votes for candidate B. Suppose these slips are removed from the box one by one. For example, one outcome is BBBAAAA. (Enter your answers in set notation. Enter EMPTY or ∅ for the empty set.) (a) List all possible outcomes. This answer has not been graded yet. (b) Suppose a running tally is kept as slips are removed. For what outcomes does A remain ahead of B throughout the tally?

In: Math

consider the following numbers: -5,-3,-1,1,3. assuming that these numbers are the sample data, use a pencil...

consider the following numbers: -5,-3,-1,1,3. assuming that these numbers are the sample data, use a pencil and calculator to calculate the mean, standard deviation and variance. please show work

In: Math

what is the average age in the class? what is the average feeling? what is the...

what is the average age in the class? what is the average feeling? what is the average city?

32 Cedar Rapids 3
24 Cedar Rapids 3
34 Marion 4
23 Coralville 2
24 Iowa City 0
35 Solon 0
26 Waterloo 3
31 Marion 3
20 Marion 2
32 Cedar Rapids 3
30 Cedar Rapids 4
34 Cedar Rapids 2
26 Cedar Falls 3
47 Cedar Rapids -3
31 Cedar Rapids 3
29 Coralville 0
29 North Liberty 0
33 North Liberty 2
44 Cedar Rapids 3
40 Williamsburg 3
40 Cedar Rapids 2
31 Marion 1
28 Cedar Rapids 0
28 Robins 3
26 Cedar Rapids 4
27 Marion 3
48 Solon 1
22 Wever 2
35 Marion 3
27 Cedar Rapids 3
27 Dubuque 3
38 Riverside -1
27 Center Point 0
28 Center Point 2
27 Cedar Falls 3
26 Cedar Rapids 1
24 Iowa City 2
54 Iowa City 2
25 Cedar Rapids 0
26 North Liberty 1
27 Dubuque 2
25 Dubuque 2
26 North Liberty 5
27 Cedar Rapids 0
24 Cedar Falls 2
30 North Liberty 1
24 Cedar Rapids 0
24 Waterloo 2
26 North Liberty 5
27 Cedar Rapids 0
25 Cedar Rapids 4
26 Cedar Rapids 3
24 Coralville 3
24 Cedar Rapids 3
31 Marion -3

In: Math

Each front tire on a particular type of vehicle is supposed to be filled to a...

Each front tire on a particular type of vehicle is supposed to be filled to a pressure of 26 psi. Suppose the actual air pressure in each tire is a random variable. X for the right tire and Y for the left tire, with joint pdf.

f(x,y) = k(x2 + y2), when 20 ≤ x ≤ 30, 20 ≤ y ≤ 30, and

f(x,y) = 0 (otherwise)

A. What is the value of k.

B. what is the probability that both tires are underfilled?

C. What is the marginal distribution of air pressure in the right tire?

In: Math