1.A recent poll of 1800 people showed that 35% believe gas prices will go down. Find the best point estimate of the proportion of all people who believe gas prices will go down.
A 35
B .30
C .65
D .35
2. A researcher wants to estimate the mean rade point average of all current college students in the United States. She has eveloped a procedure to standardize scores from colleges using something ther than a scale between 0 and 4. How many grade point averages must be btained so that the sample mean is within 0.1 of the population mean? Assume hat a 90% confidence level is desired. Also assume that a pilot study showed hat the population standard deviation is 0.88. A15
B 298
C 1
D • 210
3. Assume you want to construct a 98%
confidence interval with a sample of n = 10 from of a normally distributed
population. Find the critical value t a/2.
A • 2.764
B• 2.821
C• 1.383
D• 3.250
4. Construct a 99% confidence interval for the population standard deviation of white blood cell count (in cells per microliter).
Assume 7 random samples were selected from a population that has a normal distribution. The sample has a mean of 7.106 cells and a standard deviation of 2.019 cells
A• 1.098 < o < 4.973
B• 4.042 < o ≤ 21.170
C• 1.148 < o < 6.015
D• 1.319 < o ‹ 36.181
5. The standard deviation of duration times (in seconds) of the Old Faithful geyser is less than 40 sec. Identify the null hypothesis and alternative hypothesis in symbolic form.
A • HO: 0 < 40 sec; H1: 0 = 40 sec
B• HO: 0 = 40 sec; H1: 0 < 40 sec
C• HO: 0 = 40 sec; H1: 0 ≠ 40 sec
D• HO: 0 = 40 sec; H1: 0 > 40 sec
6.Clinical trials involved treating flu symptoms with a new medicine. Among 724 patients treated with the medicine, 72 experienced a side effect of nausea. The claim is that the rate of nausea is greater than the 6% rate #5 experienced by flu patients given a placebo. Find a test statistic of the proportion
A z=-1.41
B z=4.47
C z=4.53
D z= 1.41
7. A watch designer claims that men have wrist breadths with a mean equal to 9 cm. A simple random sample of wrist breadths of 72 men has a mean of 8.91 cm. The population standard deviation is 0.36 cm.
Assume a confidence level of a = 0.01. Find the value of the test statistic z using formula below
A 2.12
B -1.27
C 0.06
D -2.12
8. Use the following information to find the test statistic of the sample used to test the claim that FICO credit scores are greater than 675.n = 50, modifying above ×( with bar) = 719, s = 92
A t=-3.382
B t= 32.437
C t=3.382
D t=- 32.437
9. A simple random sample of 26 precipitation amounts has a standard deviation of 0.18. Find the test statistic, using a 0.01 significance level to test a claim that the standard deviation of all precipitation amounts is equal to 0.25.
A 13.478
B 18.000
C 12.960
D 48.225
10. In a test of a particular weight loss program weights of 40 subjects are recorded before and after the program. The before and-after weights result in a correlation coefficient of 0.876. Assuming a 0.05 significance level, find the critical values. Is there sufficient evidence to support the claim of a linear correlation between before-and-after weights?
A Critical values = 10.312; there is sufficient evidence to support a claim of a linear
B Critical values = +0.312; there is not sufficient evidence to support a claim of a linear
correlation between before-and-after weights.
C Critical values = +0.402; there is sufficient evidence to support a claim of a linear
correlation between before-and-after weights.
D Critical values = +0.402; there is not sufficient evidence to support a claim of a linear
correlation between before-and-after weights.
11. y (hat) = 2,060 - 0.186x is the line of
regression of a table of values comparing full-front crash repair costs to full-rear crash repair costs for a certain model sedan. Use the equation to predict the full-rear repair cost from a full-front repair cost of $4,594.
A 13,624
B 1,206
C 2,915
D 22,639
12. A linear model is given for the data in the table y=10x+1
X Y
1 9
2 21
3. 29
4. 41
5. 49
6. 61
7. 69
A 8
B -8
C -16
D 16
13. A scatterplot containing several values is found to have a linear regression R^2 value of 0.883, a quadratic regression R^2 value of 0.537, an exponential regression R^2 value of 0.492, and a logarithmic regression R^2 value of 0.912. Which mathematical model best fits the scatterplot?
A linear model
B quadratic model
C exponential model
D logarithmic model
D (logarithmic model)
Please I need help this is due for connection academy
1. The best point estimate of the proportion of all people who believe gas prices will go down is A) 35%.
2. The number of grade point averages that must be obtained so that the sample mean is within 0.1 of the population mean, with a 90% confidence level and assuming a population standard deviation of 0.88, is D) 210.
3. The critical value tα/2 for a 98% confidence interval with a sample size of n = 10 from a normally distributed population is A) 2.764.
4. The 99% confidence interval for the population standard deviation of white blood cell count is B) 4.042 < σ < 21.170.
5. The null hypothesis and alternative hypothesis in symbolic form for the claim that the standard deviation of duration times of the Old Faithful geyser is less than 40 sec are B) H0: σ = 40 sec; H1: σ < 40 sec.
6. The test statistic of the proportion for the claim that the rate of nausea is greater than 6% is B) z = 4.47.
7. The value of the test statistic z, assuming a confidence level of α = 0.01, for the claim that the mean wrist breadth of men is equal to 9 cm, with a sample mean of 8.91 cm, a population standard deviation of 0.36 cm, is D) -2.12.
8. The test statistic t, for the claim that FICO credit scores are greater than 675, with a sample size of n = 50, a sample mean of 719, and a sample standard deviation of 92, is B) t = 32.437.
9. The test statistic for testing the claim that the standard deviation of all precipitation amounts is equal to 0.25, with a sample standard deviation of 0.18 and a significance level of 0.01, is A) 13.478.
10. The critical values for a correlation coefficient of 0.876, assuming a significance level of 0.05, are A) Critical values = 10.312. There is sufficient evidence to support a claim of a linear correlation between before-and-after weights.
11. Using the regression equation ŷ = 2,060 - 0.186x, the predicted full-rear repair cost from a full-front repair cost of $4,594 is A) $13,624.
12. Using the linear model y = 10x + 1, the value of y for x = 8 is B) -8.
13. The mathematical model that best fits the scatterplot with R^2 values of 0.883, 0.537, 0.492, and 0.912 is D) logarithmic model.