Help with a couple statistics questions?
2.Comparing Variation: Which do you think has more variation: the incomes of a simple random sample of 1000 adults selected from the general population, or the incomes of a simple random sample of 1000 statistics teachers? Why? 1. z Score: When Reese Witherspoon won an Oscar as Best Actress for the movie Walk the Line, her age was converted to a z score of -0.61 when included among the ages of all other Oscar-winning Best Actresses at the time of this writing. Was her age above the mean or below the mean? How many standard deviations away from the mean is her age?
Could anyone help me with a couple of these statistics questions? Any help is appreciated!?
standard deviation of what? mean of what? well just going of the questions as far as the first two 6a. and 6b. your already given the mean and standard deviation unless you didn't finish the question. 6c. first get the Z scores z= (X -M)/ Q x minus mew divided by standard deviation Z = (1,097 - 1,100)/ 80 Z = (-3)/80 Z = -0.0375 Round of if you like ----> -0.04 find the area on the tble for Standard normal distrubution or Z score chart. 0.04 = 0.0160 now do the same for 1,104 Z = (1,104 - 1,100)/ 80 Z = ( 4 )/ 80 Z = 0.05 are for Z = 0.05 is 0.0199 Now add the area together 0.0199 + 0.0160 = 0.0359 The probability of the 400 batteries having a mean life of 1,097 to 1,104 days is 0.0359 --------------------------------------...
A couple of Statistics Questions?
1.) A radio station wants to know if residents in their area are in favor of a proposed tax increase. They invite listeners to call in to respond to the poll. 645 of the 800 who responded were against the tax. The station calculated a 95% confidence interval and declared "Between 77.9% and 83.4% of residents oppose the new tax." A. We can't say for certain that between 77.9% and 83.4% of residents oppose the new tax because it is a 95% confidence interval. B. Because of the way the poll was conducted, the results are invalid. C. This is a valid interval, so the station must be right. 2.) A statistics instructor wants to know if an expensive computer program will help his students learn. He tries the program on a section of 35 students one semester and finds a P-value of 0.078 when comparing the class' average grade to that of the semester before. The vendor, still confident about the program's potential success, lets him try it again. That time, the P-value for the test was 0.006 with a class of 150 students indicating the students did better on average, with the program. What's the difference? A. The second class had more students — a larger sample size. B. The second class was smarter. C. There were probably some outliers that affected the analysis
I have a few Statistics problems that I need help on. Could someone help me please?
1. B. -1.28 z = (0.612-0.700)/(sqrt( (0.612)(0.388))/sqrt(50)) 2. D. E(X) = np = (50)(0.20) = 10 SD(X) = sqrt(np(1-p)) = sqrt( (50)(0.20)(0.80) ) = 2.828
I have a few Statistics problems that I need help on. Could someone help me please?
1. Which of the following cannot be a probability? A. square root of 5/3 B. -87 C. D. 0.001 2. A study of 1000 randomly selected flights of a major airline showed that 758 of the flights arrived on time. What is the probability of a flight arriving on time? A. 500/379 B. 121/500 C. 500/121 D. 379/500 3. Construct a 95% confidence interval for the population mean, . Assume the population has a normal distribution. In a random sample of 26 computers, the mean repair cost was $132 with a standard deviation of $31. 4. The events A and B are mutually exclusive. If P(A) = 0.1 and P(B) = 0.6, what is P(A or B)? A. 0 B. 0.7 C. 0.06 D. 0.5 5. Assume that male and female births are equally likely and that the birth of any child does not affect the probability of the gender of any other children. Find the probability of at most three boys in ten births. A. 0.300 B. 0.003 C. 0.333 D. 0.172
I have a few Statistics problems that I need help on. Could someone help me please?
1. The scores of the top ten finishers in a recent LPGA Valley of the Stars Tournament are listed below. 71, 67,67,72,76,72,73,68,72,72 Find the mode score 2. Which of the following cannot be a probability? A. square root of 5/3 B. -87 C. D. 0.001 3. A study of 1000 randomly selected flights of a major airline showed that 758 of the flights arrived on time. What is the probability of a flight arriving on time? A. 500/379 B. 121/500 C. 500/121 D. 379/500 4. If one card is drawn from a standard deck of 52 playing cards, what is the probability of drawing a red card? A. 1/2 B. 1/13 C. 1/52 D. 1/4 5. The distribution of Master's degrees conferred by a university is listed in the table. Major Frequency Math 216 English 207 Engineer 75 Busn. 176 Edu. 222 What is the probability that a randomly selected student graduating with a Master's degree has a major of Engineering? Round your answer to three decimal places.
Need help on a couple statistics problems thx. please explain how you got answer thx very much?
A fair coin is tossed four times, and each time the coin lands heads up. If the coin is then tossed 1996 more times, how many heads are most likely to appear for these 1996 additional tosses? (a) 996 (b) 998 (c) 1000 (d) 1996 (e) None of the above. The answer is __________________________. In a particular game, a fair die is tossed. If the number of spots showing is either four or five, you win $1. If the number of spots showing is six, you win $4. And if the number of spots showing is one, two, or three, you win nothing. You are going to play the game twice. 5. The probability that you win $4 both times is (a) 1/6 (b) 1/3 (c) 1/36 (d) 1/4 (e) 1/12 6. The probability that you win at least $1 both times is (a) 1/2 (b) 4/36 (c) 1/36 (d) 1/4 (e) 3/4
How should I prepare for statistics questions for a data science interview? What topics should I brush up on?
Thanks for A2A.Actually bunch of people have written good answers and i personally liked that of Jeffrey Wong and Nigel Clay.Just to add my two cents, when it comes to selecting right candidates, i personally give emphasis on mainly two things: the conceptual understanding than mere theory, and passion to learn new things. i have seen enough people in my life who are just too good at theory but when it comes to practical implementation, they can not apply that knowledge to solve the business problem.And by chance if you stumbled upon such person in the interview who is looking for specific answer only and doesn't care about the systematic approach, i would say that company (or at least that person's job) is not for you! There are few opportunities in life which you have to let go so that some much better opportunity is waiting for you in the future! Its not just philosophy but i have (and am) experienced (and experiencing) it!I am sure the original questioner's interview must be over long back but still all the best for future interviews of all the readers! :)
I have a few statistics problems that I need help on. Could someone help me out please?
1. Find the area under the standard normal curve to the left of z = 1.5. A. 0.5199 B. 0.7612 C. 0.9332 D. 0.0668 2. Find the area under the standard normal curve between z = 1.5 and z = 2.5. A. 0.9938 B. 0.9332 C. 0.0606 D. 0.9816 3. IQ test scores are normally distributed with a mean of 100 and a standard deviation of 15. An individual's IQ score is found to be 90. Find the z-score corresponding to this value. A. 1.33 B. -0.67 C. 0.67 D. -1.33 4. IQ test scores are normally distributed with a mean of 104 and a standard deviation of 17. An individual's IQ score is found to be 110. Find the z-score corresponding to this value. A. 0.35 B. -2.83 C. 2.83 D. -0.35 5. IQ test scores are normally distributed with a mean of 100 and a standard deviation of 15. Find the x-score that corresponds to a z-score of -1.645. A. 82.3 B. 75.3 C. 91.0 D. 79.1