#### How to Calculate the Coefficient of Determination

You are estimating the cost of optical sensors based on the POWER OUTPUT of the sensor. You decide to calculate the coefficient of determination (R^2) as part of determining the goodness of fit of an equation. Using the preliminary calculations below, calculate the R^2 and determine its meaning. Σ(...

#### Counting, probability and normal probability plot

(a) The financial database of a company is secured by a password protection system. Each employee is given a randomly generated password containing three letters and two numbers. If repetitions of letters and numbers are not allowed, how many possible passwords are there? (b) Tickets for inte...

#### Exercises with Z-Scores and Percentiles

Six steps of hypothesis testing are: Identify populations, comparison distribution, and assumption; state null and research hypothesis; determine characteristics of the comparisons distribution; determine critical values, or cutoffs; calculate test statistic; and make a decision. Question 7...

#### Z-score of sample means

Compute a z statistic for each, assuming the population has a mean of 100 and a standard deviation of 20: Formula is z = (x - μ) / σ a. sample of 43 scores has a mean of 101: - 2.9 b. sample of 60 scores has a mean of 96: - 1.8 c. sample of 29 scores has a mean of 100: -3.55

#### Computing Probability and Deciding Extreme Samples

Please explain how to solve. I have attempted to answer, please let me know if I'm right or wrong. Thank you! a random sample of n=9 scores is selected from a normal distribution with u= 80 and o=12. what is the probability that the sample mean will be between 76 and 84? * 0.9974 *0.3830 * 0.2...

#### Sample Mean and Population Mean: Standard Deviation

Please explain how to set up and solve. I have attempted to answer, please let me know if right or wrong... A sample of n= 36 scores is selected form a population with o= 12. if the sample mean of M=56 produces a z score of z= +3.00 then what is the population mean? * 56 *52 (is this correct?)...

#### SD and SE Questions

For a particular population, a sample of n=4 scores has a standard deviation error of 6. for the same population a sample of n=16 scores have a standard error of *3 * 8 *2 *6 A sample of n=16 scores has a standard deviation of 4. what is the standard deviation of the population from which th...

#### Expected value of sample mean

A sample of n=100 scores is selected from a population with u= 80 with o= 20. on average how much error is expected between the sample mean and the population mean? * 0.8 points * 4 points * 0.2 points * 2 points If random samples, each with n=4 scores, are selected from a normal populati...

#### Means, standard errors, expected values

For a population with u=80 and o=20, the distribution of sample means based on n=16 will have expected value of _____ and a standard error of ____. * 80; 1.25 (this is the one i had chosen at 1st?) * 80; 5 * 5; 80 * 20; 20 Samples of n=16 scores are selected from a population. If the distrib...

#### Tattoos and Attractiveness

There is some evidence indicating that people with visible tattoos are viewed more negatively than people without visible tattoos. In a similar study a researcher first obtains overall ratings of attractiveness for a woman with no tattoos shown in a color photo. On a 7 point scale the woman receives...

#### Hypothesis Testing for One Sample Z Test

There is a popular belief that herbal remedies such as ginkgo biloba and ginseng may improve learning and memory in healthy adults, these effects are usually not supported by well controlled research. in a typical study a researcher obtains a sample of n=16 participants and has each person take a he...

#### Sample Mean - Typical or Extreme Value

Please explain how to solve this simple steps. I'm having such a hard time getting this stuff! A normal distribution has a mean of u=60 and a standard deviation of o=18. For each of the following samples, compute the z scores for the sample mean, and determine whether the sample mean is a typical, ...

#### Z-score calculation in simple steps

Please explain how to solve this. In simple steps please. A population with a mean of u=80 and a standard deviation of o=12 find the z-score corresponding to each of the following samples. M= 83 for a sample of n= 4 scores z=___ M= 83 for a sample and n= 16 scores z=___ M= 83 for a sample and ...

#### Standard Error calculations for population

A population has a standard deviation of o=20, how large a sample is necessary to have a standard error that is: Less than or equal to 5 points? n>______ Less than or equal to 2 points? n>______ Less than or equal to 1 point? n>______ If I have a sample of n=25 scores, what is the value o...

#### investment science questions

9. There are two propositions: (a) I flip a coin, If it is heads, you are paid \$3; if it is tails, you are paid \$0. It costs you \$1 to participate in this proposition. You may do so at any level, or repeatedly, and the payoffs scale accordingly. (b) You may keep your money in your pocket (earning no...

#### Conditional Probabilities and Malaria

A medical test for malaria is subject to some error. Given a person who has malaria, the probability that the test will fail to reveal the malaria is 0.06. Given a person who does not have malaria, the test will correctly identify that the person does not have malaria with probability 0.91. In...

#### Probability and Statistics Questions

1. A large shipment of computer chips is known to contain 8% defective chips. Suppose you select 500 chips at random. (a) What distribution does the number of defective chips in the sample of 500 satisfy? (Please characterize its relevant parameters.) (b) Suppose that you wish to calculate...

#### Expected Number of Lives Saved by the Defibrillator

Suppose that over the next several years, there will be 100 cardiac incidents at Silver's. Without a defibrillator, 30 victims will die before paramedics arrive. With a defibrillator, there is an 80% probability of saving a victim who would die without it. However, there is a 3% probability that ...

#### Confidence Interval & Hypothesis Testing: Cure Rate

A standard surgery was performed on 50 patients with severe sinus infection, and 36 were cured. a) Find a 95% confidence interval for the population cure rate or proportion. =0.5955, 0.8445 b) Do these data indicate that the population cure rate or proportion is more than 70%? Do a hypothesis...

#### Normal Probabilities with Z-Score

I need some help figuring this question out: Let x be a random variable that represents the speed of the first vehicle passing an observation point between 11am to 12n on a remote highway, automatically recorded by a police radar. Based on past recording over many days, the random variable has an ...

#### Probability Questions

Looking for assistance to make sure I am calculation answers correctly for the following 2 scenarios. Please provide the answer and any formulas in excel spreadsheet. A standard deck of playing cards consists of fifty-two cards. The cards in each deck consist of four suits, namely spades (♠...

#### Statistics: Finding Confidence Intervals

Using the spread sheet that is attached, develop 95% and 99% confidence intervals for the following: The mean hours per week that individuals spend in their vehicles,the average number of miles driven per week, the proportion of individuals who are satisfied with their vehicle and the proportion of...