Prof. Gersch knows that the score on a standardized test is perfectly normal with unknown mean and a standard deviation of 50.  He then takes a random sample of 25 tests and finds that the average of these is 200. How many exams should he sample so that the maximum margin of error for his 95% confidence interval is 10?:       a. 98   b. 97   c. 100   d. 96   e. 10

Q: sample of 36 students to answer the question, “How anxious do you feel when you know you have to do…

A: Given that  Sample size (n) =36 Sample mean (x¯) = 58 Sample Standard deviation (s) = 30 Confidence…

Q: Wyatt earned a score of 670 on Exam A that had a mean of 750 and a standard deviation of 50. He is…

A: Here both exam A and exam B are normally distributed. We need to find the marks required in exam B…

Q: If the scores on a test have a mean of 26 and a standard deviation of 4, what is the z score for a…

A: We want to Z-score

Q: John works as a "sanitation engineer" for a zoo that has only 10 elephants and 8 zebras in the whole…

A: Given elephants = 10 and zebras = 8 n = 18 x¯ = 1700μ = 1500σ = 500 α = 0.05

Q: Students receive an A+ on a 60 point test if they score 55 points or more.  The marks of a large…

A: Given: X~N(μ,σ)μ=50σ=5

Q: what percent of the students scored higher than 68?

A: It is given thatMean, μ = 70Standard deviation, σ = 3Z-Score, Z = ( X - μ )/σwhere, Z be the…

Q: An article in a professional journal reports the z­-score for the study’s sample mean was z = –1.4.…

A: From the provided information,z = -1.4Sample mean (x̄) = 97Sample size (n) = 49Population mean (µ) =…

Q: How many minutes did it take him to finish the face?

A: It is given that the distribution of finishing time for men was approximately normal with mean 242…

Q: The scores on the Accuplacer test and High School GPAs are normally distributed. The Accuplacer test…

A: The distirbutions of the Accuplacer test and High School GPAs are given.

Q: The scores on a​ driver's test are normally distributed with a mean of 100.   Find the score that is…

A:

Q: Sarah's score on the second exam was 34 for which the mean of all scores was 28 and the standard…

A:

Q: Lucy got a score of 75 from her statistics class. Assuming the scores of her class formed a normal…

A: a. The pth percentile of a set of observations is the value below which, p% or (p/100) proportion of…

Q: On Bob's last history test, he had a score of 92.  Bob's z-score was -0.5, and the test's standard…

A: Solution -Given that Score in History test be X=92 Z- Score=-0.50 Standard deviation= 6 Find mean…

Q: It takes an average of 8 minutes for blood to begin clotting after an injury. An EMT wants to see if…

A: Solution:- from given information claim:  if the average of 8 minutes will increase if the patient…

Q: A professor at a local university noted that the exam grades of her students were normally…

A: The mean is 73 and the standard deviation is 11.

Q: A simple random sample of 64 observations was taken from a large population. The sample mean and the…

A:

Q: Use z scores to compare the given values. The tallest living man at one time had a height of 258 cm.…

A: It is given that the height of tallest man is 258 cm and the height of shortest man is 123.4 cm. The…

Q: Use z scores to compare the given values. The tallest living man at one time had a height of 245 cm.…

A: Determine the Z-score for the tallest man. The Z-score for the tallest man is obtained below as…

Q: The scores for female students had a mean of 146 with standard deviation of 35.   you can infer…

A:

Q: A professor gives a test to her calculus students. The scores are approximately normally distributed…

A: The normal distribution is the most useful theoretical distribution for continuous variables.…

Q: ive a life expectancy of x = 71.5 years with a standard deviation of s, = 6.6 years. A sample of 6…

A: According to guidlines we can strickly answer three subspartsRural town:Sample size Sample mean…

Q: The first exam for a Stats course had a mean of 80 and a standard deviation of 4 points; the second…

A: To identify the appropriate ranks of Reginald and Sara, the z-score, which provides the positional…

Q: How would the P-value change? The P-value would remain unchanged because the variability measured by…

A: Hypothesis is an assumption that is being tested.

Q: A psychologist wants to estimate the amount of math anxiety that the population of high school…

A:

Q: The scores on the Accuplacer test and High School GPAS are normally distributed. The Accuplacer test…

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: The systolic blood pressure of adults in the USA is nearly normally distributed with a mean of 117…

A:

Q: Jason's z- score in the 10-k run was -3. if the raw score standard deviation was 5, and the mean…

A:

Q: The scores on the Accuplacer test and High School GPAS are normally distributed. The Accuplacer test…

A:

Q: The distribution of heights of adult men is approximately normal with mean 69 inches and standard…

A: Given that information  Mean = mu = 69 inches  Standard deviation = s = 2.5 inches  Z score = -2.5…

Q: It takes an average of 9.1 minutes for blood to begin clotting after an injury. An EMT wants to see…

A: Sample size n=49Sample mean=8Standard deviation=3.31NOTE: according to bartleby guidelines expert…

Q: An environmental researcher took 30 water samples from different areas of a lake. He measured the pH…

A: The objective of the question is to understand the concept of standard deviation and interpret it in…

Q: The mean of 5 observations is 15 and variance is 9 if two more observation having values 4 and 10…

A: The mean of five observations is 15. Mean=1n.∑ixi∑ixi=5×15=75 Variance…