In an entrance test for admission 900 students appeared. Their average marks were 50 and standard deviation 20. (i). Find the number of students securing between 30 and 70 (ii) number of students exceeding the score of 65.

Q: The mean score on a standardized test is 540 with a standard deviation of 55. What percent of…

A: Given mean= 540 Standard deviation=SD= 55 We have to find the z value of 625.

Q: The mean score on a set of 25 tests is 76. What is the sum of all the test​ scores?

A: The mean (aka the arithmetic mean, different from the geometric mean) of a dataset is the sum of all…

Q: A very good professional baseball player gets a hit about 35% of the time over an entire season.…

A: Solution:- The commentator is wrong because the law of averages does not apply in this situation.…

Q: What scale of measurement is being used when a teacher measures the number of correct answers on a…

A:

Q: The class mean for the exam was 82 with a standard deviation of 6.  There are 37 students in the…

A: We have given that, Mean = 82 , standard deviation σ = 6  sample size n = 37   Standard error of the…

Q: A researcher measures the amount of food consumed by each dog in her lab. She finds that the mean…

A: It is given that mean amount of food is 12 oz and number of dogs is 16. The sum of squared…

Q: Of the 200 American film enthusiasts, the average age is: 30 years, while the standard deviation is…

A: Normal distribution is generally denser in the center, and basically less denser at the tails. There…

Q: What is the percentage of scores that lie between a z score of -2 and a z score of 1?

A:

Q: The chloride concentration in the blood (mmol / liter) averages 104 with a standard deviation of 5.…

A: Given Data: Let X represent the random variable   X~ Normal (104, 52) n=200 Therefore, X¯ ~ Normal…

Q: Karen is in her first semester at a certain university and is taking a calculus course with a large…

A: The objective of this question is to calculate the z-score of Karen's exam score and interpret it in…

Q: a.) At a = .05, is there enough evidence to show that the true mean red blood cell count in the…

A: a) The provided sample mean is Xˉ=4.932\bar X = 4.932 and the sample standard deviation is s=0.504s…

Q: The scores on a test are normally distributed with a mean of 110 and a standard deviation of 22.…

A: Let X be the random variable from Normal distribution with mean (μ) = 110 and standard deviation (σ)…

Q: how do you find the standard deviation when the score is 9 points above tthe mean?

A: = population standard deviation = the size of the population = each value from the population =…

Q: Find the proportion of scores greater than 70 mean is 90 standard deviation is 10

A: The standard normal distribution:A continuous random variable Z is said to follow standard normal…

Q: On his 5 tests, Ahmad earned a total of 450 points. What was his mean number of points earned per…

A: The objective of this question is to find the mean number of points Ahmad earned per test. The mean…

Q: on a national achievement test score was 850 with a standard deviation of 100. what proportion of…

A: The Z-score of a random variable X is defined as follows: Z = (X – µ)/σ. Here, µ and σ are the mean…

Q: Change z-score (-2.00) into X value – Mean = 50, standard deviation = 10

A: Standard normal distribution: The standard normal distribution is a special case of the normal…

Q: A random sample of 300 students was taken from an affluent school district. There were 75 students…

A: The sample size is 300, number of students who were coached for the SAT's is 75. The sample…

Q: the average (mean) score on an exam was 76.52 in a class consisting of 14 supply chain students and…

A: Answer:- Given, A class consisting of 14 supply chain students and 11 HR students.  That is, Total…

Q: Sally had a z score of +0.25 on a test with a mean of 62 and a standard deviation of 5. What was her…

A: From the provided information,Z score = +0.25

Q: Why is the sum of the sum of six deviations -2, -1, -1, -1, 0, 5 when added =0?

A: Solution:It is one of the property of sample mean that the sum of deviations above average and the…

Q: For 120 consecutive days, a process engineer has measured the temperature of champagne bottles as…

A: Given, that the process engineer measured the temperature of champagne bottles for  consecutive…

Q: The distances golf balls travel under laboratory testing conditions are normally distributed. The…

A:

Q: You received a 74% on a quiz. You are curious about how you did in the class overall and want to…

A: Since you have posted a question with multiple sub-parts, we will solve the first three sub-parts…

Q: The mean score on a set of 28 tests is 75. What is the sum of all the test​ scores?

A: The objective of this question is to find the sum of all the test scores given the mean score and…

Q: A dishwasher has a mean lifetime of 12 years with estimated standard deviation of 2.75 years. Assume…

A: It is given that:Mean lifetime of dishwasher: Standard deviation of dishwasher:

Q: The mean score on a standard test is 450 with a standard deviation of 78. What percent of the test…

A: From the given I formation, Mean score (µ) = 450 Standard deviation (σ) = 78 Thus, the required…

Q: Linda is in her first semester at a university and is taking a calculus course with a large…

A:

Q: (a) (i) Find the mean of the contractor's measurements. (ii) Calculate the percentage error between…

A:

Q: In a population distribution a score of x equals 28 corresponds to z equals -1.00 and a score of x -…

A: Given From the given information A score of X=28 Corresponds to z= -1 and a score of X=34…