A student took two national aptitude tests. The national mean and standard deviation were 375 and 100, respectively, for the first test, and 50 and 8, respectively, for the second test. The student scored 525 on the first test and 70 on the second test. Use z-scores to determine on which exam the student performed better relative to the other test takers. first exam or  second exam 2. In a study investigating the effect of car speed on accident severity, 5,000 reports of fatal automobile accidents were examined, and the vehicle speed at impact was recorded for each one. For these 5,000 accidents, the average speed was 41 mph and the standard deviation was 15 mph. A histogram revealed that the vehicle speed at impact distribution was approximately normal. (Use the Empirical Rule.)   Approximately what percentage of these vehicle speeds exceeded 56 mph? (Round your answer to the nearest whole number.) approximately__ %

Q: 2. A reading exam was conducted for 4th grade children and 9th grade children. The 4th grade…

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

Q: I have attached a picture! Thank you!

A:

Q: Given the following scores of 21 students in the Science exam:…

A:

Q: One-Sample Statistics Std. Deviation Std. Error Mean Mean hrs1 NUMBER OF HOURS WORKED LAST WEEK 895…

A: From the given output, it is clear that t test had been done. 1. The test done was One sample t test…

Q: In the 1980s, a research study linked drinking coffee to a higher risk of heart disease and pancreat…

A: Introduction: A confounding variable in a study is a variable that is not acknowledged or controlled…

Q: At a=0.05, what is the critical value? -1.984 1.66 -1.645 -1.66

A:

Q: A researcher measures the number of hours college students spend on social media in a day. 10…

A: Given data: 2, 6, 5, 3, 3, 7, 5, 5, 6, 8

Q: 1. How much of the data lies between one standard deviation from the mean, two standard deviations…

A:

Q: A) For the data in Table 1 below, how many standard deviations from the mean is a run length of 20…

A: The given data table is Female hamsters Run lengths Male hamsters Run lengths 1 2 1 3 2 6 2 4…

Q: two universities (one in the east and one in the west) are being compared.  Researchers want to know…

A:

Q: Consider the following sample data.   Consider the following sample data.   Sample A: 9, 18, 27…

A: Given data is appropriate for measures of central tendency and measures of dispersion. mean is used…

Q: What is the standard deviation for the following sample of scores? Scores: 3,2,4,6,6,3

A: The standard deviation is a measure of dispersion. It tells how much data are deviates from their…

Q: You are the director of public safety in Hinsdale. You want to evaluate two ambulance services that…

A: GivenThe mean and standard deviation of two ambulances are shown below Our objective is to choose…

Q: The following data are the GPA’s of 12 students at State University. Determine the mean, median,…

A:

Q: Saoirse took 3 classes in a semester.   The class means and standard deviations are given below:…

A:

Q: Refer to the following students score data: Score 11-14 15-18 19-22 23-26 27-30 31-34 35-38…

A: Given data; Scores(Class) Frequency (f) Mid value (x) f⋅x 11-14 4 12.5 50 15-18 7 16.5…

Q: 1b) Calculate the mean deviation from the mean for the following data: Size : 4 8. 10 12 14 16…

A: We have given that,  Date set in the form of size and frequency is,  Xi =   2    4    6    8    10…

Q: 3. Given the sample variance of a distribution, explain how to find the standard deviation.

A: Variance is the measure of dispersion that calculates the average of the squared difference from the…

Q: Given the following grades on s test: 86, 92, 100, 93, 89, 95, 79, 98, 68, 62, 71, 75, 88, 86, 93,…

A: The objective of this question is to find the percentage of scores that lie within one and two…

Q: llowing three data sets has the largest standard deviation? A (9,10,11,7,13) B(10,10,10,10,10)…

A: The Standard Deviation is given by SD=∑x-x2N Where, x is the mean of data.N is the number of terms.

Q: Which of the following exam scores is better relative to other students enrolled in the course? A…

A: The exam grade, mean grade, and standard deviation for three exams are given.

Q: A TV weatherman end of the year analysis of the local weather showed that among all the years for…

A: Z-score: The Z-score measures a particular value’s relationship to the mean, in a group of values.…

Q: c. Analyzing marks of 15 students from Spring 2020, you found their mean to be 23.6 and standard…

A: Data given Summer 2020  23,18,17,24,27,18,14,29  Spring 2020  n=15, x̄=23.6, s=4.9

Q: A study  was conducted to compare the results of two different types of behavorial rating scales,…

A: Given,  A study  was conducted to compare the results of two different types of behavioral rating…

Q: Statistics Variable N N* Mean SE Mean StDev Minimum Q1 Median Q3 Maximun length 40 4.150 0.300 1.899…

A: Summary statistics of a data length of species sunfish, bass and carp is given.

Q: What is the percentile rank for a student who scored 74 on a softball rules test if the class mean…

A:

Q: Saara, a tuck-shop operator in Okuryangava, recorded her weekly income and the number of hours…

A: Correlation coefficient is given by, r=cov(x,y)/sd(x)*sd(y) Where cov(x,y)= E(xy)-E(x)*E(y) E(xy)=…

Q: What does Chebyshev’s rule say about the percentage of observations in any data set that lie within…

A: a.We have to determine the percentage of observations in any data set that lie within six standard…

Q: Approximately, what percentage of data lies within two standard deviations from the mean?

A: Empirical rules:1) P(μ-σ<x<μ+σ)=68%2) P(μ-2σ<x<μ+2σ)=95%3) P(μ-3σ<x<μ+2σ)=99.7%

Q: Do people walk faster in the airport when they are departing​ (getting on a​ plane) or do they walk…

A: Given, α=0.05 μ1 = represent the mean speed of people departing and μ2 = represent the mean speed of…

Q: The number of patients coming into a dental clinic each day were 74, 52, and 83. a. Find the sample…

A: Given: The data of the number of patients coming into a dental clinic each day is given as:…

Q: A tire company finds the lifespan for one brand of its tires is normally distributed with a mea…

A: Z is known as standard normal variable and it's value is obtained using standard Normal table.

Q: 14) Find the score that separates the top 80% from the bottom 20% if the Mean is 100 and the…

A: Given information Mean (µ) = 100 Standard deviation (σ) = 26 The score that separates the top 80%…

Q: Which has the greatest standard error?     mean=20, s.d.=10, n=9     mean=30, s.d.=15, n=16…

A:

Q: a. Fish weights have a mean of 3 pounds and a standard deviation of 0.5 pound. What percentage of…

A: a) Fish weights have a mean of 3 pounds and a standard deviation of 0.5 pound.

Q: The three data sets listed below have the same mean and range. Compute the standard deviation for…

A: The given data sets are: Data set 1 Data set 2 Data set 3 5 5 5 7 6 5 9…

Q: 4) You are given the following data set: 11, 10, 9, 13, 11, 8, 3, Find the mode, median and mean.…

A: