A researcher wants to investigate the effects of environmental factors on IQ scores. For an initial study, she takes a sample of 400 people who grew up as the only child. She finds that 53 % of them have an IQ score over 100 . It is known that 50 % of the general population has an IQ score exceeding 100 . Find the mean of p , where p is the proportion of people with IQ scores over 100 in a random sample of 400 people. Find the standard deviation of p . Compute an approximation for P ≥ p 0.53 , which is the probability that there will be 53 % or more individuals with IQ scores over 100 in a random sample of 400 . Round your answer to four decimal places.

Q: For a sample of n = 30 scores, a score that is 6 points above the mean has a z-score of z = 1.50.…

A: For a sample of n = 30 scores, a score that is 6 points above the mean has a z-score of z = 1.50.

Q: In a college class, the average IQ is 115. Assume that the distribution is normal and that the…

A: In a college class, the average IQ is 115. Assume that the distribution is normal and that the…

Q: f the height of Grade 6 pupils is normally distributed with a mean of 64 in. And a standard…

A: The z-score is calculated asz=x-μσ

Q: The scores on a psychology exam were normally distributed with a mean of 50 and a standard deviation…

A:

Q: What z-score would be associated with the value x = 124?

A: Given that Mean = 133 SD = 6 And the value is X = 124

Q: For a sample with M= 80, a score of X= 88 corresponds to z =2. what is the sample standard deviation…

A:

Q: On a math exam, Joel had a score o 90, which was exactly 2 standard deviations above the mean. The…

A: Since, we only do up to three sub parts of a problem, we'll be doing the first three sub parts only.…

Q: What is the z score of x=30 if x is three deviations to the left of the mean?

A: From the provided information, x = 30 and it is three deviations to the left of the mean.

Q: A manager is interested in finding the average number of sales per day at a sporting goods store. If…

A: Obtain the sample size. The sample size is obtained below as follows: Use EXCEL Procedure for…

Q: A set of test papers is normally distributed with a standard deviation of 5. If Riley scored an 83…

A:

Q: For a sample with mean M=80,  a score of X=88 corresponds to z=2. What is the standard deviation?

A:

Q: find the z-score for the value 95, when the mean is 77 and the standard deviation is 2.

A: Given, mean=77 standard deviation=2 find the z-score for the value 95

Q: In a population with mean 50 what standard deviation score would have a score of X=45

A:

Q: On a final examination in Biology, the mean was 75 and the standard deviation was 12. What is the…

A: Given problem Given that   On a final examination in Biology,  The mean was = μ = 75 The standard…

Q: . For a population with a mean of µ = 70, a score of X = 64 corresponds to z = -1.50. What is the…

A:

Q: A score that is 6 points below the mean correspond. to a z-score of z = -2.00. What is the…

A: The following is the formulae for z-score                       i.e., z=X-μσ Here, X is variable…

Q: A standardized test of intelligence is scaled so that the mean IQ is 100, and the standard deviation…

A: Given that information  Mean = mu= 100  Standard deviation = s =15  Zscore = (x - mu)/s

Q: For a random sample of 40 students, the average statistics midterm score is 73 points (out of a…

A: The sample size is 40, average statistics midterm score is 73 points, and standard deviation is 7.3.

Q: A medical statistician wants to estimate the average weight loss of people who are on a new diet…

A:

Q: For a population with a standard deviation of σ = 5, what is the z-score corresponding to a score…

A: We have to find z score..

Q: An instructor in a large lecture class found, at the end of the semester, that the total point…

A: The provided information is:

Q: In a Science test, the mean score is 42 and the standard deviation is 5. Assuming the scores are…

A: Given: The mean score of a Science test is μ=42. The standard deviation is σ=5. Let X be a random…

Q: he scores on a psychology exam were normally distributed with a mean of 65 and a standard deviation…

A: Given,μ=65σ=6

Q: A score that is 6 points below the mean corresponds to a z-score of z = -1.50. What is the…

A: We have to find population standard deviation from given information. We need to use z score…

Q: In a normally distributed data set of how long customers stay in your store, the mean is 43.5…

A: Given data Mean μ = 43.5 Standard deviation σ = 3.9 95% of your customers to stay in your store.…

Q: A score that is 9 points above the mean corresponds to a z-score of z = 1.50. What is the population…

A:

Q: For a population with a standard deviation of a =6, what is the score corresponding to a score that…

A:

Q: Hello, how do you calculate this? Thank You!

A: Compute the 90% confidence interval for the population mean.Since the sample size is small and the…

Q: A teacher finds that the test scores of a group of 40 students have a mean of 72 and standard…

A: (a) A teacher finds that the test scores of a group of 40 students have a mean of 72 and standard…

Q: Assume the test scores in your class are normally distributed with a mean of 84. You scored a 96,…

A: Given: mean = 84.

Q: A score that is 20 points above the mean corresponds to a z-score of z – 1.25. What is the standard…

A: Given: z= 1.20 20 points above the mean. that is

Q: For a random sample of 10 men, the mean head circumference is x-bar= 57.3 cm and the sample standard…

A:

Q: For a population with population mean 80 and standard deviation10, what is the z-score corresponding…

A:

Q: What z-score would be associated with the value x = 172?

A: Given that Mean = 112 SD = 10 And value X = 172

Q: 32 individuals from a population and the mean of the population is 120 and the standard deviation of…

A: From the central limit theorem the sample mean blood glucose level will follow normal distribution…

Q: the golf scores for a school team were normally with a mean of 68 and a standard deviation of 3. Use…

A:

Q: On an exam, Tom scored 8 points above the mean and had a z-score of +2.00. The standard deviation…

A: Given: z-score=2 Score above the mean=8

Q: Alex wants to find out: if the standard deviation of the mean for the sampling distribution of…

A: Solution: given standard deviations of sample s1=9. fir sample size n1=256  Then what will be the…

Q: In a certain test in Calculus, the mean score of a group of 100 students was 30 and the standard…

A: The mean for calculus is 30 and standard deviation is 8, the mean for physics is 52 and standard…

Q: In a population distribution, a score of X = 28 corresponds to z = −1.00 and a score of X = 34…

A: Where, For X=28 & z=-1.00 For X=34 & z=-0.50

Q: Suppose that Jett achieves a score of 1250 on the SAT, and his sister Kate scores 29 on the ACT. The…

A: Given information- For SAT scores- Population Mean µ = 1100 Standard deviation (σ) = 250 For ACT…

Q: A student scored 76 on a general science test where the class mean and standard deviation were 82…

A: For Science x¯=82s=8x=76 z=x-x¯s=76-828=-0.75

Q: If the probability of a defective bolt is 0.1, find he mean he standard deviation for the…

A: a) If the probability of a defective bolt is 0.1. Given that there are total of 400. That is, n=400…

Q: In a test, the average of the grades is 80 and the standard deviation is 5. John's grade is 70, so…

A:

Q: An instructor in a large lecture class found, at the end of the semester, that the total point…

A: It is given that mean and standard deviation are 530 inches and 80, respectively.

Q: on an exam, Tom scores 12 points above the mean and has a z-score of z=+2.00. the standard deviation…

A: It is given that the difference between mean and raw score is 12 and the z score is 2.

Q: In a sample distribution, a score of x = 21 corresponds to z = -1.00 and a score of x = 12…

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: Assume that the results are normally distributed. Pedro took an exam in a class in which the mean…

A:

Q: What are all the values that standard deviation "s" can possibly take?

A: Standard deviation S=x1;x2n-1and ,Standard deviation is the positive squarew root of the variance…

Confidence Intervals

When we calculate intervals in probability and statistics, it can be simply termed as finding out a confidence interval. The confidence interval is usually calculated from the data set which is observed. The value of the parameter that needs to be calculated is present here only.