Now look at the variable DIFFERENCE in the data file “Fuel Efficiency.” If there is no difference between the computer-calculated and driver-calculated mpg, then the average DIFFERENCE should be zero. Calculate the 95% confidence Interval for variable DIFFERENCE. Do your calculation step-by-step and fill out the values in the diagrams below. First use Excel Descriptive Statistics to get the two important statistics: sample-mean estimate ?̅ and the standard deviation s. Fill-Up No. Computer Driver Difference 1 41.5 36.5 5 2 50.7 44.2 6.5 3 36.6 37.2 -0.6 4 37.3 35.6 1.7 5 34.2 30.5 3.7 6 45 40.5 4.5 7 48 40 8 8 43.2 41 2.2 9 47.7 42.8 4.9 10 42.2 39.2 3 11 43.2 38.8 4.4 12 44.6 44.5 0.1 13 48.4 45.4 3 14 46.4 45.3 1.1 15 46.8 45.7 1.1 16 39.2 34.2 5 17 37.3 35.2 2.1 18 43.5 39.8 3.7 19 44.3 44.9 -0.6 20 43.3 47.5 -4.2   • What is the sample mean estimate ?̅ ? ?̅= ___________________ • What is the standard deviation s of the sample? s = ___________________ What is Standard Error of the Sample Mean: sX̅ =_____________________ What is the critical value: t* = ______ (Use the t-Table, df = n - 1 = 20-1 = 19) The margin of error: m = t*× ??̅ = _____________________________________ Lower Confidence Level = ?̅- m = ___________________________________________ Upper Confidence Level = ?̅+ m = ____________________________________________

READ THE GIVEN PROBLEM AND ANSWER THE QUESTION THAT FOLLOWS. SHOW YOUR SOLUTION.  Suppose that you enter a fishing contest. The contest takes place in a pond where the fish lengths have a normal distribution with mean of 16 inches and standard deviation of 4 inches.  QUESTIONS: 1. What is the percentile rank of your catch of 10 inches? SHOW YOUR SOLUTIONS 2. What is the minimum length to belong to the upper 5% of the fish in the pond? SHOW YOUR SOLUTIONS

There are two major tests of readiness for college, the ACT and the SAT. ACT scores are reported on a scale from 1 to 36. The distribution of ACT scores is approximately Normal, with mean of 21 and standard deviation of 5.3. SAT scores are reported on a scale from 400 to 1600. The distribution of SAT scores is approximately Normal, with mean of 1,042 and standard deviation of 209.  What SAT scores make up the top 15% of all the scores?  Round to the nearest whole number.

A population has mean 27 and standard deviation 12 . What is the data value that has a z-score of -2 ? Write only a number as your answer.   I got -2.42. Is that the correct answer?

Calcium is essential to tree growth because it promotes the formation of wood and maintains cell walls. In 1990, the concentration of calcium in precipitation in a certain area was 0.15 milligrams per liter (mg/L). A random sample of 10 precipitation dates in 2007 results in the following data table. Complete parts (a) through (c) below. E Click the icon to view the data table. (a) State the hypotheses for determining if the mean concentration of calcium precipitation has changed since 1990. Ho: 0.15 mg/L H1: 0.15 mg/L

HELP PLEASE

Here is a FDT for a small data set: data freq 45 2 46 4 47 2 48 3 49 9 Find the following measures of central tendency.mean = median = mode =

Each problem describes a research situation and the data it produces. Identify the statistical procedure or test that is appropriate for the data. Choose whether the problem requires one of the following: Descriptive statistics (Mean, Standard Deviations, Percentiles), one-sample t-test, Independent-measures t-test, Independent-measures ANOVAs (One-factor or Two-factor), Repeated-measures ANOVA, Linear Regression, Chi-Square Goodness-of-fit, Chi-Square Test of independence. 1) Research has demonstrated that IQ scores have been increasing, generation by generation, for years (Flynn, 1999). A researcher would like to determine whether this trend can be described by a linear equation showing the relationship between age and IQ scores. The same IQ test is given to a sample of 100 adults who range in age from 20 to 85 years. The age and IQ score are recorded for each person.   2) Childhood participation in sports, cultural groups, and youth groups appears to be related to improved…

Fitting a straight line to a set of data yields the following prediction line. Predict the mean value of Y for x=5

Identify the type of data that would be used to describe a response. Number of Mt. SAC students selected to go on a UCLA college campus tour. Qualitative Quantitative - Discrete O Quantitative - Continuous