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Z-Test

Altmans z

Who would use Altman's Z score to predict bankruptcy? Why would the ability to predict bankruptcy be useful to them?

Z-score distribution

A distribution has a standard deviation of 0=4. Find the z-score for each of the following locations in the distribution. a. Above the mean by 4 points b. Above the mean by 12 points c. Below the mean by 2 points d. Below the mean by 8 points

Z-test for accident rates

In Dallas some fire trucks were painted yellow. During the test period, the fleet of red fire trucks made 153,348 runs and had 20 accidents. the fleet of yellow trucks made 135,035 runs and had 4 accidents. At a=.01, did the yellow fire trucks have a significantly lower accident rate? Zc=2.326 Z=2.961 p-value=.0015 normal

Corresponding Z-Scores Percentiles

#1 With regards to a standard normal distribution complete the following: (a) Find P(z < 0), the percentage of the standard normal distribution below the z-score of 0. (b) Find P(z < 1.65), the percentage of the standard normal distribution below the z-score of 1.65 (c) Find P(-3 < z

Vehicle Mileage Statistical Analysis

The Environmental Protection Agency (EPA) fuel economy estimates for automobile models tested recently predicted a mean = 24.8 miles per gallon and a standard deviation a = 6.2 miles per gallon for highway driving. Assume a normal distribution. Use this information to answer questions #13 - #14. (13) Use Table 4 (Standard

Z test for population mean number of arrivals per hour

9.22 The mean arrival rate of flights at O'Hare Airport in marginal weather is 195 flights per hour with a historical standard deviation of 13 flights. To increase arrivals, a new air traffic control procedure is implemented. In the next 30 days of marginal weather the mean arrival rate is 200 flights per hour. (a) Set up a rig

Hypothesis test for the difference of population means: Z test

Please see attached file for full problem. Hypothesis test for the difference of population means: Z test According to the historical data, the life expectancy in the United States is equal to the life expectancy in Japan. A new study has been made to see whether this has changed.

Identifying the Z Score

Question: The height in inches of girls on a high school girls basketball team are as follows: 60.0 61.0 62.5 64.0 66.5 Identify the z score used in a quantile plot for the player with a height of 66.5 inches. z=

Another Special Cases of Z-scores

Briefly explain what percentages of the cases in the normal curve you can obtain by using a z-score of 2.58 as a cutoff point. Specifically: A. Discuss the percentages in the middle area (near the mean). B. Discuss the percentages in the tails.

Basics of Z-scores: draw a normal curve, and shade in your answer.

You know that 34.13% of the cases lie between the mean and a z-scores of +1.00. For each answer, draw a normal curve, and shade in your answer. A. What percentage liew between the mean and a z-score +1.00? B. What percentage lies in the tail above a z-score of +1.00 C. What percentage of the cases lies between a z- scores

Find the z value

What is the z value to the right of the mean such that 85% of the total area lies to the left?

A five-year old study claims that selling prices of new homes / condominiums in the New York area have a normal distribution with mean = $180,000 and standard deviation = $40,000.

A five-year old study claims that selling prices of new homes / condominiums in the New York area have a normal distribution with mean = $180,000 and standard deviation = $40,000. a. Assuming that the results of the study are still valid, what is the probability that a randomly selected new house in the New York area will cos

Analysis of a T-Test and Z-Test

Perform hypothesis testing on one variable's data. (Choose either the intrinsic or extrinsic column.) Perform a t-test by formulating a null and an alternative statement, choosing an acceptable significance value, selecting the test statistic and determining its value from the sample data, comparing the observed value to the cri

Percentages?

Question 2. The number of patrons attending the local sports bar each evening during footballs season follows the normal distribution. The mean number of patrons per evening is 240 and the standard deviation is 35. a) What percent of the evenings will have between 185 and 240 patrons? b) What percent of the evening wi

Standard Deviation Calculations

Find the standard deviation for the given data. Round your answer to one more decimal place than the original data. 54) 15, 42, 53, 7, 9, 12, 14, 28, 47 54) ______ A) 15.8 B) 29.1 C) 17.8 D) 16.6 Use the empirical rule to solve the problem. 55) The systo

Z-score question

The standard normal table shows an area value of 0.1 for a z-score of 0.25 and an area value of 0.35 for a z-score of 1.04. What percentage of the observations of a random variable that is normally distributed will fall between 0.25 standard deviations below the mean and 1.04 standard deviations above the mean?

One sample z test for population proportion.

The election is one week away. You think you have the election sewn up, but the seem appears to be unraveling. You run a poll, draw a random sample of 500 adults. 54% say they will vote for your candidate. Will your candidate win? Prove it.

Population Proportion Statistics

If you just want to make a prediction about the proportion of nurses (and not do a z-test), you'll have to find more data points. You could sample several different employers, or look at different departments within the place where you work. In either case, you'd have many different proportions in your sample. You would calcu

Statistics Project: Estimating Parameters

Conduct pilot studies about a mean and a proportion aspect of the place where you work. Find sample mean/proportion and use these results to make estimates of the corresponding population parameters. See attached file for full problem description. The population where I work is 5000 employees. I was going to do a proportion

Chebyshev: Normal Populations and testing

5. Consider an infinite population with a normal shape and a mean of 300 and standard deviation of 30. a. Compute the z-scores for the following values of X and locate each on the graph. X Z-score 200 360 220 270 300 b. According to the Empirical rule what percent of the data should be between 270 and 330? Betw

HYPOTHESIS TESTING

Here is a sample of 106 body temperatures (attached file) with a mean of 98.20 F. Assume that &#963; is known to be 0.62 F. Consider a hypothesis test uses a 0.05 significance level to test the claim that the mean body temperatures of the population is less than 98.6F. a. What is the test statistic? b. What is the critical

Finding probability using a normal distribution

1.) A normal distribution has a mean=60 and a standard deviation=6. Find the following probabilities: p(X>56) p(X<70) p(52<X<68) p(61<X<75) 2.) A normal distribution has a mean=35 and standard deviation=5. Find the scores associated with the following regions: a.) the score needed to be in the 43rd percentile. b.) T

Indicate the mean and standard deviation for this distribution.

#1.) Dr.Radman has been collecting data on a simplified intake form. One measure that was taken was the amount of time (in minutes) it took people to complete this form. The time to complete the simplified form was Mean=22 minutes and Standard Deviation= 3 minutes (assume there were enough forms completed to justify using popula

Determination of Critical value, Significance level, p value for Z test

Question 1 (Basic Business Statistics Tenth Edition Q 7.53.) DiGiorno's frozen pizza has some of the most creative and likeable advertisements on television. USA Today's Ad Track claims that 20% of viewers like the ads "a lot"" (Theresa Howard, "DiGiorno Campaign Delivers Major Sales," www.usatoday.com, April 1, 2002). Su

When to use a t-test and when to use a z-test

When to use a t-test and when to use a z-test. How to choose between a t-test and a z-test, a one-sample test and a two-sample test, and a one-sided and a two-sided test. Lists the assumptions made about the sample and the population for each test.