Finding Areas under the Normal Curve. Finding Normal Values Corresponding to an. Normal Probability Plots. Confidence Intervals about µ,. Unlike its predecessors, Minitab for the Mac doesn't give the user additional. Use sample scores to obtain a 90% confidence interval for population mean score. Find the correlation r and the regression equation; produce a fitted line plot.

STATE COLLEGE, PA., Dec. 9, 2015 (GLOBE NEWSWIRE) -- Minitab Express 1.4, an update to the most recent version of this statistical software package for introductory statistics, adds new analyses and features.

'We're excited to provide business and engineering departments with the tools they need to prepare students for aMinitab Express does the heavy lifting with the calculations,' says Paret. 'It allows students to focus on learning statistical concepts and their applications in real-world problem solving.'

Row and column statistics now calculate figures such as row averages, and users can create formulas using new percentile, concatenate, combinations, permutations, factorial, and logic functions.
New features added to Minitab Express 1.4's graph and random data tools enable users to fit exponential, lognormal, or Weibull distributions for histograms and probability plots, use the geometric distribution when calculating and graphing probability distributions, and generate data sets sampled from geometric or Bernoulli distributions.

Instructors also have access to new lesson plans for teaching core statistical concepts using Minitab Express or Minitab 17. Class outlines, instructor notes, exercises, answer keys, and Minitab data sets are included.

The update is free for Minitab Express users. More information about Minitab Express, including pricing, licensing, a free 30-day trial version, and the new lesson plans are available at www.minitab.com/academic.

About Minitab Inc.

Minitab Inc. is the leading provider of statistical software for quality improvement worldwide. More than 4,000 colleges and universities use Minitab for teaching and research. Thousands of companies in more than 100 countries trust Minitab.

The company's products include:

• Minitab® 17, the leading statistical software used for quality improvement and statistics education.
• Minitab Express™, is designed for teaching and learning introductory statistics and is available for both the Mac and PC.
• Quality Trainer by Minitab®, an e-learning course that teaches statistics and how to use Minitab Statistical Software.
• Devize®, a powerful Monte Carlo simulation tool for engineers.
• Qeystone®, a project portfolio management platform designed to manage an organization's entire Lean Six Sigma deployment.
• Quality Companion by Minitab®, process improvement software for executing quality improvement projects.

Minitab's products are backed by free technical support and outstanding services, including training, statistical consulting and custom development.
Headquartered in State College, Pa., Minitab Inc. operates offices in Phoenix, Az., the United Kingdom, France, and Australia and has additional representatives throughout the world.

A photo accompanying this release is available at: http://www.globenewswire.com/newsroom/prs/?pkgid=38068

New to confidence intervals? Here are some important things to keep in mind!

Confidence Intervals:

• are used to estimate population parameters (commonly the process mean, standard deviation, % of defective units, or even capability indices).
• provide more meaningful information than any random sample statistic for characterizing the population.

MINI-TIP:
See “Tip 1: Every sample statistic is a little bit wrong.”

When your 95% confidence interval for the mean is (μ_low, μ_high), you can be 95% confident that the population (process) mean, μ, is between μ_low and μ_high …and 5% confident that μ is not between μ_low and μ_high.

When your 95% confidence interval for the standard deviation is (σ_low, σ_high), you can be 95% confident that the population standard deviation, σ, is between σ_low and σ_high …and 5% confident that s is not between σ_low and σ_high.

MINI-TIPS:
Multiply the high estimate for σby 6 to approximate the potential range of a normal distribution. Multiplying the sample standard deviation, σ, by 6 tells us nothing about the population.

When your 95% confidence interval for the proportion of defectives is (p_low, p_high), you can be 95% confident that the process is producing at least p_low x100% defectives, and potentially as many as p_high x100% defective units.

For example, suppose you inspect 100 units and find 2 defectives. The sample % defective is 2%. But, using Minitab's 1 Proportion study, we create the 95% confidence interval for the proportion of defectives: (0.0024, 0.070). So this sample may be from a process that is producing a whopping 7% defective units!

Users should carefully consider how much CPU, Memory and hard disk will be available to the Windows OS, this is of course based upon how many cores and memory is available in the MacBook.

TAKE-AWAY PERSPECTIVE:
There is always some RISK that even the confidence intervals will not contain the parameter of interest. That said, just imagine how risky it is to assume any sample statistic adequately characterizes the population!

More Facts About Confidence Intervals:

• INCREASING the % confidence INCREASES the length of the interval.
• INCREASING the sample size DECREASES the length of the interval.

MINI-TIP:
Use Minitab’s ‘Power and Sample Size for Estimation’ to determine sample sizes necessary to create confidence intervals of meaningful length.

• INCREASING the sample size does not increase the likelihood that the interval will contain the population parameter. Only increasing % confidence does this.

TAKE-AWAY PERSPECTIVE:
Confidence intervals based on small samples are as credible (reliable) as those based on large samples.

• The true population parameter may be near one end of the confidence interval.

TAKE-AWAY PERSPECTIVE:
Do not assume that the parameter of interest is near the middle of the interval.

• A 95% Confidence Interval DOES NOT contain 95% of the individual values in the population.

MINI-TIP:
Use Minitab’s ‘Tolerance Intervals’ to create intervals that capture a desired percent of the individual population values, with a given degree of confidence.

In Tip 4, we'll provide a brief explanation of tolerance intervals.

To gain more perspectives on statistical analysis procedures using Minitab Statistical Software, visit Minitab's web site for course descriptions and training opportunities, both public and on-site, at http://www.minitab.com/en-us/services/training/