Dear Sir, Please explain Sampling Distribution & Confidence interval.

A confidence interval is an estimated range of values which provides an upper and lower limit likely including an unknown population parameter. Confidence interval is calculated from certain confidence level. It actually provides the probability that our estimates are correct.

Whereas, sampling distribution is a type of distribution that involves the probability distribution of sample statistics based on randomly selected samples.

It can be of any statistic – mean, a median, a percentage, etc. It is a distribution of the probabilities for each value of the statistic from the repeated samples.

Sampling distribution is calculated by finding the probabilities for each of the values given in the frequency tables. For calculating the probabilities, the frequency of each value divided by the total number of samples is calculated. Let’s add this probability column to our tables.

boys’ age






.1 (=1/10)
















Average = 7.95


A o A What is content analysis? And explain the best way to apply? Plz explain it in easy words and examples.

Content analysis is a technique for gathering and analyzing the content of a text on a particular topic.  The content refers to words, meanings, pictures, symbols, ideas, themes, or any message that can be communicated. The text is anything written, visual, or spoken that serves as a medium of communication. Possible sources for the study could be newspaper or magazine, books, articles, advertisements, poems, letters, laws, constitutions, dramas, speeches, official documents, films or videotapes, musical lyrics, photographs, articles of clothing, or works of arts. For example someone is given the task to examine the document and ask questions about the content. For finding the answer of those questions, he would start collecting the relevant material. For this he may use magazines, books, articles or contact several people to find information and analyze the collected content and text to satisfy the questions arose in his mind.

A o A sir Plz explain the term placebo in easy words with suitable example plzzzzzzz

placebo, a simulated false treatment, which is medically ineffectual treatment for medical condition intended to deceive the recipient. This is mostly used in examining the effects of the new drugs for a particular disease. For example, a researcher wants to know that medicine is effective or not. He will use the 2 or 3 different types of pills, one of them is original drug (medicine) and others will be placebo pills (sugar capsules or pills). Subjects will know only that they are taking medicine for their disease. The caretaker will also be unaware of the whole situation to get the true results and will give them medicine and note down the subjects health condition. For detail information follow this link.

Sir plz explain Instrumentation Effects?

Instrumentation effect is one of the types of extraneous variable that can affect internal validity of experiment. Instrumentation effect refers to change in measuring instrument between pretest and posttest. For example, you want to conduct a weight loss experiment. In order to ensure internal validity in an experiment you must have sound instrument that takes exactly same reading at pretest and posttest.

What is the meanings of Data reduction???

Data reduction is in fact process of the reduction in number of data by eliminating the invalid and void data for converting data into corrected, ordered, and simplified form. For detail information, you may explore the following link.

Sir,What is the meanings of Normal disrtibution and Skewed distribution? also tel me with examples?

A normal distribution is sometimes referred to as a “bell-shaped distribution” because data is evenly and symmetrically distributed where the mean, median and mode all coincide.

But in skewed distribution, data is not evenly distributed and has “asymmetry” in a “bell curve” as shown in following diagram. It may be positively or negatively skewed. For detail information, you may explore the following link.

Sir, what are the meanings of Ordinal scale and Nominal scale? also tell me with examples???

A nominal scale is way of categorizing or grouping behavior, where the actual numbers are simply labels or identifiers without any order or structure. ”Nominal” scales could simply be called as “labels.”  For example gender can be categorized as male and female.

An ordinal scale is basically set of rankings like it interprets gross order but does not describe the relative importance.  For example Social economic class of respondents (low, middle, high)