Calculate the expected value, the variance, and the standard deviation of the given random variable X. (Round all answers to two decimal places.) X is the number of red marbles that Suzan has in her hand after she selects four marbles from a bag containing four red marbles and two green ones. expected value variance standard deviation
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- A Show Time Remaining A The body lengths of deer mice are known to vary approximately normally, with mean 86 mm and standard deviation 8 mm. A research group is interested whether vitamin supplements will increase deer mouse body length. They select a random sample of 100 deer mice from the population of all deer mice that would ever receive vitamin supplements and observe their body lengths. Suppose the sample mean is calculated as 87.2 mm. Let u be the mean body length of deer mice who receive vitamin supplements. Provide the null and alternative hypotheses most appropriate for this situation. O A. Ho: H = 86 vs. Ha: P> 86 B. Họ: H = 87.2 vs. Hạ: µ 87.2 Reset SelectionMidterm exam scores are normally distributed with a mean of 75 and a standard deviation of 6. If the exam is given to 10,000 students, we would expect No one to receive a score of 87 No one to have received a score below 63 Half the scores to fall between 70 and 83 NO Half the scores to fall between 64 and 88 Just over one third of the scores to fall between 75 and 81QS- Entry to a certain University is determined by a national test. The scores on this test are normally distributed with a mean of 500 and a standard deviation of 100. Tom wants to be admitted to this university and he knows that he must score better than at least 70% of the students who took the test Tom takes the test and scores 585. Will he be admitted to this university? b-80.23% No a 80.23% Yes 72.4% Yes Q6- A company has 10 software engineers and fo 4 enginoore ha far 0.567 d-0.675 brity of races. e-0.776 are
- A random sample of 100 selected from a population with a standard deviation of 10 yielded a mean = 225. The mean and the standard deviation of the distribution of the sample means are ____________. 225 and 10 225 and 1 225 and 0.1 22.5 and 1 22.5 and 10Calculate the expected value, the variance, and the standard deviation of the given random variable X. (Round all answers to two decimal places.) X is the number of red marbles that Suzan has in her hand after she selects three marbles from a bag containing three red marbles and two green ones. expected value variance standard deviationScores Probability 0 4 5 6 8 10 12 0.1 0.25 0.05 0.15 0.15 0.05 0.25 Find the mean of the above random variable. Find the standard deviation of the above random variable. Find the variance of the above random variable. Use all digits in your answer for the standard deviation to calculate the variance. If necessary, round your answers to 3 decimal places.
- Accordi the historical data, the life expectancy in Mexico is equal to the life expectancy in Spain. A new study has been made to see whether this has changea. Records of 205 individuals from Mexico who died recently are selected at random. The 205 individuals lived an average of 71.8 years with a standard deviation of 2.6 years. Records of 250 individuals from Spain who died recently are selected at random and independently. The 250 individuals lived an average of 71.2 years with a standard deviation of 3.0 years. Assume that the population standard deviation of the life expectancy can be estimated by the sample standard deviations, since the samples that are used to compute them are quite large. At the 0.05 level of significance, is there enough evidence to support the claim that the life expectancy, H1, in Mexico is not equal to the life expectancy, µ,, in Spain anymore? Perform a two-tailed test. Then complete the parts below. Carry your intermediate computations to at least three…An insurance company is looking over accident statistics. They want to model the population of all drivers for the population parameter of the standard deviation and variance of the age of the driver involved in an automobile accident. They have a sample of 100 accidents from around the country. The age of the driver in each of these accidents is provided below. Use Excel to calculate the sample standard deviation and the sample variance. Round your answers to one decimal place. Do not round until you've calculated your final answer "Age of people in accident"48643346436728189044472440202747683248472248217347302918487364454920205066654187873417203176493089672222455023481746382942254720463119214227226621236675744621461969202048238851284918204522313823284939 Standard deviation: Variance:It is believed that 58% of Americans like to eat at restaurants every week. You interview 6 Americans and ask if they like to eat at restaurants every week. The random variable x represents the number of Americans that like to eat at restaurants every week. Find the mean of the binomial distribution. μ = ____________________________ Find the standard deviation of the binomial distribution. σ = __________________________ What is the probability that at least 1 of the Americans surveyed likes to eat at restaurants every week? Provide an answer to 4 decimal places.
- Temperature in degrees Fahrenheit has been collected from a sample of 50 individuals. The mean is 98.5 and standard deviation is 3.2. If we convert each observation into degrees in the centigrade scale ((X°C × 9/5) + 32 = Y°F) then what would be the new mean and standard deviation of the set of temperatures?reliability engineeringesc Introduction A chain of restaurants has historically had a mean wait time of 9 minutes for its customers. Recently, the restaurant added several very popular dishes back to their menu. Due to this, the manager suspects the wait time, μ, has increased. He takes a random sample of 44 customers. The mean wait time for the sample is 9.6 minutes. Assume the population standard deviation for the wait times is known to be 3.3 minutes. Can the manager conclude that the mean wait time is now greater than 9 minutes? Perform a hypothesis test, using the 0.05 level of significance. (a) State the null hypothesis Ho and the alternative hypothesis H₁. Ho: O H₁:0 (b) Perform a Z-test and find the p-value. Here is some information to help you with your Z-test. The value of the test statistic is given by Standard Normal Distribution Step 1: Select one-tailed or two-tailed. O One-tailed O Two-tailed Explanation μ Check □<口 X X OSO 020 0=0 x-H √n • The p-value is the area under the curve to the right…