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Independent or Dependent Samples, Z-test, Critical Value

1. Classify as independent or dependent samples: The average price of gasoline at ten local stations, and the average price of gasoline at ten stations in another state. independent dependent 2. Classify as independent or dependent samples: The number of crimes committed in Pittsburgh, and the number of

Statistics: Does the Bowman-to-downtown route meet the STA criterion?

The policy of the Suburban Transit Authority (STA) is to add a bus route if more than 45% of the potential commuters indicate they would use the particular route. A sample of 70 commuters revealed that 39 would use a proposed route from Bowman Park to the downtown area. Does the Bowman-to-downtown route meet the STA criterion? U

Hypothesis Testing of Mean: Z Test

A process is supposed to produce aluminum castings with a mean weight of 1.223 kg. The weights follow a normal distribution with known standard deviation 0.084 kg. (a) Set up hypotheses and a two-tailed decision rule to detect quality control violations using the .05 level of significance. (b) From the following sample of 12

Significance Level

10-29: According to the local union president, the mean gross income of plumbers in the Salt Lake City area follows the normal probability distribution with a mean $45,000 and a standard deviation of $3,000. A recent investigative reporter for KYAK TV found, for a sample of 120 plumbers, the mean gross income was $45,000. At the

Z Score to retain funding

Please show how to set this problem up. I am totally lost. Do I need to determine the Standard Deviation, etc.? Please give me a step by step way to work this problem Calculate the average student score necessary for the district to retain its federal funding. You may assume that the Standard Deviation will not change. Thi

Probability - Coke and Pepsi

Please help with the following problems. Give step by step calculations. Can you can tell the difference between coke and pepsi in a blind taste test? Most people say they can and have a preference for one brand or another. However, research suggests the people can correctly identify a sample of one of these products only 60

P Value for Z test for proportions.

Please answer the following question using the P value approach. Please describe your answer in detail. The answer details are important to my understanding the P value concept. The manager of the circulation department of a newspaper claimed that 75% of subscribers would renew their subscriptions. A sample of 100 subscribe

Z test for proportion of blower accident data

Men are usually the snow blower accident victims. There are several factors to consider, but we're going to choose the level of operating experience between men ages 21-35. We selected 32 men between the ages of 21 and 35 who'd been in snow blower accidents that caused finger amputations. 16 of the men had no experience operatin

Hypothesis Testing: Z Test and Difference of Proportions

In the year 2000, the state of Indiana began a $40-million renovation of its state fairgrounds, which included the building of a miniature golf course and a state-of-the-art livestock building. Now, Indiana officials are interested in learning what sorts of people are visiting the new attractions. In a survey done at this year's

Z test for proportion of election data.

A presidential candidate's aide estimates that, among all college students, the proportion p who intend to vote in the upcoming election is at least 60%. If 137 out of a random sample of 235 college students expressed an intent to vote, can we reject the aide's estimate at the 0.05 level of significance? Perform a one-tailed

Z scores of the World's Tallest Women

1. Heights of Presidents. With a height of 67 in., William McKinley was the shortest president of the past century. The presidents of the past century have a mean height of 71.5 in. and a standard deviation of 2.1 in. a. What is the difference between McKinley's height and the mean height of presidents from the past century?

One sample Z test for mean

A Survey is conducted to determine the mean number of minutes per day that teens between the age of 16 and 18 spend watching television per day. A previous study showed that the population standard deviation was 21.5 minutes. The organization selected a random sample of n = 200 teens between the ages of 16 and 18 and recorded th

Z Test Using Megastat

Question: Suppose the federal government proposes to give a substantial tax break to automakers producing midsize cars that get a mean mileage exceeding 31 mpg. A sample of 49 midsize cars showed a mean of 31.5 mpg, with a standard deviation 0.8. [Use Excel- Megastat, hypothesis tests, the mean v hypothesized value, a z-test or

Conducting Z test for population proportions

Please help with the following problem. Media Disk, Inc. duplicates over a million 3.5" floppy disks each year by copying masters to stacks of blank disks. The company buys its blank stock from two different suppliers, A and B. The manager has decided to check each supplier's stock by counting the rejected disks in the next

Probability calculation for for normal variable

Given that z is a standard normal random variable and that the area to the right of z is 0.1949, then the value of z must be A) 0.51 B) -0.51 C) 0.86 D) -0.86 Your high school graduating class had 564 members. Thirty-three percent of these are expected to attend college. The probabili

Probabilities and z-score

If a student had a z-score of 1, what would be the raw score (rating)? If a student had a z-score of 1, what percentage of the participants would be expected to rate the product higher than he/she did? If a student gave a rating of 75, what would be the z-score? What is the probability that a rating is bel

Z score and T score calculation

On a test whose distribution is approximately normal with a mean of 50 and a standard deviation of 10, the results for three students were reported as follows: Student Opie has a T-score of 60. Student Paul has a z-score of -1.00. Student Quincy has a z-

Z-test and p-value

Please see attached file. I just need to know what the test statistic is and the p-value. Hypothesis test for the difference of population means: Z test According to the historical data, the life expectancy in Germany is less than or equal to the life expectancy in the United States. A new study has been made to see whether

In Dallas, some fire trucks were painted yellow (instead of red) to heighten their visibility. During a test period, the fleet of red fire trucks made 153,348 runs and had 20 accidents, while the fleet of yellow fire trucks made 135,035 runs and had 4 accidents. At á = .01, did the yellow fire trucks have a significantly lower accident rate?

Please see attachment. In Dallas, some fire trucks were painted yellow (instead of red) to heighten their visibility. During a test period, the fleet of red fire trucks made 153,348 runs and had 20 accidents, while the fleet of yellow fire trucks made 135,035 runs and had 4 accidents. At á = .01, did the yellow fire trucks h

One sample Z test..

The mean employee turn over at Ms. Jameelah's employment of 280 employees hired for the different new position each year is 20 with standard deviation of 4.6. It is now assumed that because of the down turn in the economy, the turn over has decreased to less than 20 in average. A random sample of 90 employees from 280 total show

Hypothesis test : Z test for corporate executives

A researcher was interested in determining whether corporate executives who exercised regularly scored lower than corporate executives in general on a scale of stress symptoms. For corporate executives in general, the average on this test is 80 with a standard deviation of 12. The researcher then measured 20 executives who exerc

Z test of Hypothesis for the Mean...

9.32 A manufacturer of salad dressing uses machines to dispense liquid ingredients into bottles that move along a filling line. The machine that dispenses dressings is working properly when the mean amount dispensed is 8 ounces. The population standard deviation of the amount dispensed is different from 8 ounces. Suppose that th

Calculate and Interpret Z Score

Using the data set below, can you tell me if any variable for any observation is appropriate for the calculation of a z score. If it is please explain how to calculate and interpret a z score on that variable. If it is not please tell me why it isn't appropriate for this data set. Title Year Rating Budget ($) Gross ($) L

Predictions for GM

Calculate GM's Altman Z-Score. Show your calculations. Based on the Z- Score: Do you predict that GM will go bankrupt in the near-term? Explain Based on your calculations, would you agree or disagree with Lutz that GM is over the worst? Explain in detail.

Random Samples from Two Binomials

This exercise is a "what if analysis" designed to determine what happens to the test statistics and interval estimates when elements of the statistical inference change. This can be solved manually or on Excel with Test statistics or Estimators workbook. Random samples from two binomial populations produced the following stat

Percentage and z-score

The weight for a group of 18 month-0ld girls are normally distributed with a mean of 24.4 pounds and a standard deviation of 2.6 pounds. Use the table to find the percentage of 18 month-old girls who weigh more than 27.8 pounds. z-score1. 0.1, 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Percentile 53.98, 57.9,

Sample proportions and test statistic for equal proportions

Find the sample proportions and test statistic for equal proportions. Is the decision close? Find the p-value. a. Dissatisfied workers in two companies: x1 = 40, n1 = 100, x2 = 30, n2 = 100, α = .05, twotailed test. b. Rooms rented at least a week in advance at two hotels: x1 = 24, n1 = 200, x2 = 12, n2 = 50, α