In: Math
The following statistics are calculated by sampling from four normal populations whose variances are equal: (You may find it useful to reference the t table and the q table.)
x¯1 = 169, n1 = 5; x¯2 = 179, n2 = 5; x¯3 = 172, n3 = 5; x¯4 = 162, n4 = 5; MSE = 55.8
a. Use Fisher’s LSD method to determine which population means differ at α = 0.05. (Negative values should be indicated by a minus sign. Round intermediate calculations to at least 4 decimal places. Round your answers to 2 decimal places.)
Population Mean DifferencesConfidence IntervalCan we conclude that the population means differ?μ1 − μ2[,]μ1 − μ3[,]μ1 − μ4[,]μ2 − μ3[,]μ2 − μ4[,]μ3 − μ4[,]
b. Use Tukey’s HSD method to determine which population means differ at α = 0.05. (If the exact value for nT – c is not found in the table, then round down. Negative values should be indicated by a minus sign. Round intermediate calculations to at least 4 decimal places. Round your answers to 2 decimal places.)
Population Mean DifferencesConfidence IntervalCan we conclude that the population means differ?μ1 − μ2[,]μ1 − μ3[,]μ1 − μ4[,]μ2 − μ3[,]μ2 − μ4[,]μ3 − μ4[,]
In: Math
You are testing the null hypothesis that there is no linear relationship between two variables, X and Y. From your sample of n=18, you determine that b1=4.4 and Sb1=1.3
a. What is the value of t stat?
b. At the a=0.05 level of significance, what are the critical values?
c. Based on your answers to (a) and (b), what statistical decision should you make?
d. Construct a 95% confidence interval estimate of the population slope,β1.
In: Math
Suppose that we want to test the hypothesis that mothers with low socioeconomic status (SES) deliver babies whose birthweights are different than "normal". To test this hypothesis, a list of birthweights from 69 consecutive, full-term, live-born deliveries from the maternity ward of a hospital in a low-SES area is obtained. The mean birghweight is found to be 116 oz. Suppose that we know from nationwide surveys based on millions of deliveries that the mean birthweight in the United States is 120 oz, with a standard deviation of 23 oz. At α = .06, can it be concluded that the average birthweight from this hospital is different from the national average? (a) Find the value of the test statistic for the above hypothesis. (b) Find the critical value. (c) Find the p-value.
In: Math
For high risk group screening (i.e. injection drug users) as compared to generla population screening, what is the best in terms of levels of sensitivity and specificity. Explain why.
In: Math
3300 Econometric HW
obs | RWAGES | PRODUCT |
1959 | 59.87100 | 48.02600 |
1960 | 61.31800 | 48.86500 |
1961 | 63.05400 | 50.56700 |
1962 | 65.19200 | 52.88200 |
1963 | 66.63300 | 54.95000 |
1964 | 68.25700 | 56.80800 |
1965 | 69.67600 | 58.81700 |
1966 | 72.30000 | 61.20400 |
1967 | 74.12100 | 62.54200 |
1968 | 76.89500 | 64.67700 |
1969 | 78.00800 | 64.99300 |
1970 | 79.45200 | 66.28500 |
1971 | 80.88600 | 69.01500 |
1972 | 83.32800 | 71.24300 |
1973 | 85.06200 | 73.41000 |
1974 | 83.98800 | 72.25700 |
1975 | 84.84300 | 74.79200 |
1976 | 87.14800 | 77.14500 |
1977 | 88.33500 | 78.45500 |
1978 | 89.73600 | 79.32000 |
1979 | 89.86300 | 79.30500 |
1980 | 89.59200 | 79.15100 |
1981 | 89.64500 | 80.77800 |
1982 | 90.63700 | 80.14800 |
1983 | 90.59100 | 83.00100 |
1984 | 90.71200 | 85.21400 |
1985 | 91.91000 | 87.13100 |
1986 | 94.86900 | 89.67300 |
1987 | 95.20700 | 90.13300 |
1988 | 96.52700 | 91.50600 |
1989 | 95.00500 | 92.40800 |
1990 | 96.21900 | 94.38500 |
1991 | 97.46500 | 95.90300 |
1992 | 100.00000 | 100.00000 |
1993 | 99.71200 | 100.38600 |
1994 | 99.02400 | 101.34900 |
1995 | 98.69000 | 101.49500 |
1996 | 99.47800 | 104.49200 |
1997 | 100.51200 | 106.47800 |
1998 | 105.17300 | 109.47400 |
1999 | 108.04400 | 112.82800 |
2000 | 111.99200 | 116.11700 |
2001 | 113.53600 | 119.08200 |
2002 | 115.69400 | 123.94800 |
2003 | 117.70900 | 128.70500 |
2004 | 118.94900 | 132.39000 |
2005 | 119.69200 | 135.02100 |
2006 | 120.44700 | 136.40000 |
Problem 2.
Use the data in the “Autocorrelation” tab to test
For Autocorrelation using the Durbin Watson Test
Graph the Residuals and determine whether they are distributed normally or whether they are biased
In: Math
A biologist is sampling oranges to determine the amount of juice in each orange. She tested 50 oranges chosen at random. The average amount of juice was = 3.1 ounces with a standard deviation of σ = 0.4 ounces. Find a 95% confidence interval for the population mean number of ounces of juice in an orange.
elect one: a. 2.85 < μ < 3.35
b. 3.04 < μ < 3.16
c. 2.99 < μ < 3.21
d. 3.14 < μ < 3.21
In: Math
Calculate ??/2 for each of the following. Illustrate your answers with graphs.
a. ? = 0.10
b. ? = 0.01
c. ? = 0.05
d. ? = 0.20
In: Math
In: Math
is there any scenarios when can a low R2 value be acceptable?
In: Math
A statistics teacher wants to see if there is any difference in the abilities of students enrolled in statistics today and those enrolled five years ago. A sample of final examination scores from students enrolled today and from students enrolled five years ago was taken. You are given the following information.
today (population 1) Five years ago (population 2)
sample mean 86 88
sample variance 112.5 54
sample size 45 36
The 92.50% confidence interval for the difference between the two population means is (round your answer to 2 decimal places).
In: Math
In a multiple linear regression model with 2 predictors (X1and X2), TRUE or FALSE
In a multiple linear regression model with 2 predictors (X1and X2), then SSR(X1)+SSR(X2|X1) = SSTO–SSE(X1,X2) TRUE or FALSE
In a multiple linear regression model with 2 predictors (X1and X2), if X1and X2are uncorrelated, SSR(X1) = SSR(X1|X2). TRUE or FALSE
In a multiple linear regression model with 2 predictors (X1and X2), SSR(X1) + SSR(X2|X1) = SSR(X2) + SSR(X1|X2). TRUE or FALSE
In simple linear regression, then (X’X)-1is 2x2. TRUE or FALSE
In simple linear regression, the hat-matrix is 2x2. TRUE or FALSE
In: Math
What other descriptive data would be useful for providing clues as to the causes of female breast cancer?
In: Math
Television advertisers base their investment decisions regarding the promotion of their products and services on demographic information about television viewers. The age of the viewers is a key factor in their process. The following table shows the number of hours that a random sample of individuals watched television during the week. The individuals are grouped according to their ages. Minitab is required. You will need to enter the data into Minitab.
Age Group |
|||
18-24 |
25-34 |
35-49 |
50-64 |
49 |
41 |
44 |
39 |
33 |
40 |
19 |
14 |
33 |
33 |
27 |
15 |
39 |
35 |
36 |
17 |
71 |
21 |
49 |
20 |
a. At the 0.05 level of significance, determine if there is a difference in the mean number of hours of television watched by age group. State your hypotheses and show all 7 steps clearly. (14 points)
b. Give and interpret the p-value. (3 points)
c. Should Tukey pairwise comparisons be conducted? Why or why not? (3 points)
d. If appropriate, use Minitab to produce Tukey pairwise comparison. Write a few sentences with your conclusions from those comparisons. (4 points)
e. Use Levene’s test to determine if the assumption of homogeneity of variances is valid. Give the hypotheses, test statistic, p-value, decision, and conclusion. Use the 0.05 level of significance. (8 points)
f. Verify with Minitab by attaching or including relevant output. (6 points)
In: Math
A distribution and the observed frequencies of the values of a variable from a simple random sample of the population are provided below. Use the chi-square goodness-of-fit test to decide, at the specified significance level, whether the distribution of the variable differs from the given distribution.
Distribution: 0.3, 0.2, 0.2, 0.2, 0.1
Observed frequencies: 12, 9, 8, 17, 4
Significance level = 0.10
In: Math