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Hypothesis Testing

Probability, hypothesis testing and confidence intervals

What is an important similarity between the uniform and normal probability distributions? A. The mean, median and mode are all equal. B. The mean and median are equal. C. They are negatively skewed. D. About 68% of all observations are within one standard deviation of the mean. The distribution of the annual incomes of a

Hypothesis Testing - Heating and Oil Company

The director of Heating and Oil at Superior Oil Company is concerned about the high cost of home heating oil being offered to their customers for the upcoming Fall season in Philadelphia, PA. The company has no possibility of modifying the oil price under the current economic conditions. He believes that the company should off

Alternative Hypothesis and Level of Significance

Please help me with the following: 1. Write a correct alternative hypothesis for: Ho: µ ? 35. 2. Answer "True" if the statement is always true. If the statement is not always true, replace the words shown in bold with words that make the statement always true. The (1 ? ?) is known as the level of significance of a hypothe

Hypothesis Testing Sample Questions

1. Measurements of the left handed and right handed gripping strengths of twelve left handed persons are recorded as follows. PERSON 1 2 3 4 5 6 7 8 9 10 11 12 LEFT HAND 140 90 125 130 95 121 85 97 131 110 98 109 RIGHT HAND 138 87 110 132 96 120 86 90 129 100 101 117 We wish to test whether left handed persons have greater

Calculating sample size based on population proportion

With a 90% confidence interval, what size sample would we need based on the proportion of population in proportion to sample size? Null hypothesis: There is a taste difference between the two brands so consumers will be able to identify the difference in brand seventy percent of the time. The alternate null hypothesis assert

Cost Curve Anaylsis

You have been presented with the following cost data table and asked to fit a statistical cost function. Quantity | 10 | 20 | 30 | 40 | 50 | 60 | 70 | 80 |

Data analyses

Attached are data from 2 populations; the first population consists of subjects numbered Combined-POS-1 thri 156 that have been tested for CD4 % LYMPHOCYTES (pos) WBC (X1000/ul) (pos) HB (g/dl) (pos) PLATELETS (x1000/ul) (pos) The second population consists of subjects numbered Combined-NEG-1 There are 642 that have al

Data Analysis: Oreo and Market Pantry Cookies

Fort he attached data set perform a z-test for proportion and z-test for both brand names. Find the cutoff value for z, sample proportion, standard error, confidence intervals, one and two-tailed test, critical values, and lower/upper limits.

Life expectancy hypothesis testing

On a sample of 50 US married couples, it has been found that on average females live longer (80 years) than males (75 years). a) Using the fact that the corresponding standard deviations are thought to be σ female = 3 and σ male = 4 years respectively, determine if this data indicate that female live longer than males, us

True Correlation Significant

Size of Data Set: 100 Regression equation/line: Y=11.20816-0.1098466x Slope is -0.1098466 The y-intecept is 11.20816 Sum of Regression Bar Errors^2=16.6051535247 Sum of YBar Errors=188.830557742 R/correlation coefficient: -0.955020 R^2/coefficient of determination:= 0.912063 X and Y values from the Scatter Plot Points

Hypothesis Testing and Assessing Levels of Significance

Perform the following hypothesis tests on the data in spreadsheet HW #1. State the conclusion of the hypothesis tests. The level of significance is 0.05 in each test. 1. The claim that the average Median SAT is over 1200. 2. The claim that the proportion of schools with Expenditures/Student over $50,000 is 0.2. 3. The claim

Statistics Problem Set: Buena School District Bus

1. In a market test of a new chocolate raspberry coffee, a poll of 400 people from Dobbs Ferry showed 250 preferred the new coffee. In Irvington, 170 out of 350 people preferred the new coffee. To test the hypothesis that there is no difference in preferences between the two villages, what is the alternate hypothesis? a. H1: p1

Sampling and Hypothesis Testing Questions

1. Find the critical value X2 0.99 associated with a X2 curve with 10 degrees of freedom. 2. Find the critical value having an area of 0.05 to its right for an F-curve with 8 numerator degrees of freedom and 15 denominator degrees of freedom. 3. A random sample of 100 adults was recently gathered in order to explore a poss

Do actively managed funds fail to outperform the overall market?

It is believed that most actively managed funds fail to outperform the overall market. To empirically test this statement, an analyst has collected the following secondary data to examine whether or not the mean return of an index which represents all the actively managed funds in the market is statistically different from the a

Statistics Problem: Bacteria in Carpeted Rooms

Researchers wanted to determine if carpeted rooms contained more bacteria than uncarpeted rooms. To determine the amount of bacteria in a room, researchers pumped the air from the room over a Petri dish at a rate of 1 cubic foot per minute for eight carpeted rooms and eight uncarpeted rooms. Colonies of bacteria were allowed to

Conducting and Econometrics Analysis

Please see the attached file. An investigator analysing the relationship between food expenditure, disposable income and prices in the US using annual data over the period 1959-83 computes the following regression log(FOOD) = 4.7377 + 0.1069TIME + 0.3506log(PDI) - 0.5086log(PRICE) (0.6805) (0.0033) (0.0899

Statistics Problem Set: Confidence Level

1) For the following sequence: 2,4,7,3,9,4,7,11 find the range, mode, median, mean, IQR, standard deviation, variance and whether it is normally distributed (with explanation) 2) An investor wants to assess at confidence level of 98% if a medicament can improve the marks of students. He notices that for the following daily

Using Statistics to Analyze a Scenario

Scenario: You are interested in researching a new ambulance dispatching method. The new method is supposed to be more efficient and uses half the communications personnel of the old method, saving over $300,000 annually. You want to know how the new method compares to the old method in terms of how many minutes it takes ambulanc

Interpreting the P-Value

In 280 trials with a professional touch therapist, correct responses to a question were obtained 1223 times. The P-value of 0.979 is obtained when testing the claim that p > 0.5 (the proportion of correct responses is greater than the proportion of 0.5 that would be expected with random chance). What is the value of the sample p

SPSS Experimental Analysis - Diet of Rats

See the attached file. A researcher interested in studying the effects of three experimental diets with varying fat contents on the total lipid (fat) level in plasma collected the data in the file FatInDiet.txt. Fifteen male subjects who were within 20 percent of their ideal body weight were grouped into five blocks accor

Statistics Problem: Patient Illness

A study was performed on patients with a particular illness. The standard deviation of the weights of 12 patients with the illness was 21.4 kg. A control group of 5 patients without this illness had a standard deviation of the weights of 12.4 kg. Prove if the weights of the patients with this illness are (or are not) more vari

Statistics Problem: Mean Wait Time

A bank manager has developed a new system to reduce the time customers spend waiting for teller service during peak hours. The manager hopes that the new system will reduce waiting times from the current 9 to 10 minutes to less than 6 minutes. Suppose that the manager wishes to use 100 waiting times to support the claim that th

Hypothesis Testing: Milk Volume Example

Quart cartons of milk should contain at least 32 ounces. A sample of 22 cartons contained the following amounts in ounces. 31.5 32.2 31.9 31.8 31.7 32.1 31.5 31.6 32.4 31.6 31.8 32.2 32.1 32.1 31.6 32.0 31.6 31.7 32.0 31.5 31.9 32.8 a) What set of hypotheses should be tested if we want to demonstrate th

Standard Deviation, Average Number & P-Value Questions

1) The club professional at a difficult public course boasts that his course is so tough that the average golfer loses a dozen or more golf balls during a round of golf. A dubious golfer sets out to show that the pro is fibbing. He asks a random sample of 15 golfers who just completed their rounds to report the number of golf

Baby Birth Weights and Mother Cocaine Use Study

A random sample of the birth weights of 186 babies has a mean of 3103g and a standard deviation of 696g (based on data from "Cognitive Outcomes of Preschool Children with Prenatal Cocaine Exposure," by Singer et al., Journal of the American Medical Association, Vol. 291, No. 20). These babies were born to mothers who did not us

Non-Parametric Test on Software Adoption

Company W is testing a sales software. Their sales force of 500 people is divided into four regions: Northeast, Southeast, Central and West. Each sales person is expected to sell the same amount of products. During the last 3 months, only half of the sales representatives in each region were given the software program to help th

Statistical Testing - T Tests and Proportions

1. Do men and women have different beliefs on the ideal number of children in a family? Based on the following GSS2008 Data and the obtained t statistics, what would you conclude? (0.05) Men Women Mean ideal number of children 3.06

Relative Risk Example Problem

A multicenter clinical trial involving 17,000 patients suspected of having acute myocardial infarction was conducted. The vascular death rate after 5 weeks was compared in patients receiving aspirin versus those not receiving aspirin, regardless of any other concomitant treatment. The relative risk (RR) for the effect of aspirin