normal distribution

Which statement is the characteristic of the t distribution that are not for the standard normal distribution? => The variance is greater than 1. or The mean, median and mode are equal to 0 and are located at the center of distribution. or The distributi..

Mr. John gave his students a test in the class. The scores were normally distributed with a mean of 75 and standard deviation of 4. What percent of the students scored between 71 and 79? => 95% or 99.7% or 68% or 34%..

Monthly expenditures for a family of four in a city averages $450, with a standard deviation of $65. Assume the monthly expenditures are normally distributed. Find the probability that a family whose expenditure will be less than $294 or greater than $554. => 0.063 or 0.0548 or ..

An organization conducted a test for a group of students, whose scores are normally distributed with mean 70 and standard deviation 3. Find the probability that the score of a particular student is greater than 67. => 0.8413 or 0.1587 or 0.3413 or 0.5000..

Students of a class were given an aptitude test. Their scores were found to be normally distributed with mean 65 and standard deviation 7. What percent of the students scored between in the range 51 - 72? => 47.72% or 81.85% or 34.13% or 13.59%..

Suppose the number of games in which major league baseball players play during their careers is normally distributed with mean equal to 1,500 and standard deviation equal to 350 games. What percentage play in fewer than 750 games? => 98.39% or 1.62% or 48.39% or 51.62%..

Find the 95% confidence interval for the variance of the ages of players in a basketball team if a sample of 12 players has a standard deviation of 2 years. Assume the variable is normally distributed. => between 2 and 10 or between 2 and 13 or between 2 and 14 or between 2 and ..

To qualify as a contestant in a swimming event, a swimmer has to be in the top 20% of all entrants. The swimming times are normally distributed, with a mean of 70 min and a standard deviation of 3 min. What is the qualifying time for the event to the nearest minute? => 66.4 min ..

Scores in statistics obtained by students of a class are normally distributed. If 12.5% obtain 60% scores and above and 39% less than 30, then find the mean and the standard deviation of the scores. => 36.55, 20.98 or 35.89, 28.90 or 39.85, 29.80 or 35.88, 20.98..

A random sample of 81 students was tested for the problem solving approach skills. The variance of the scores obtained from the sample was found to be 144. Find the 80% confidence interval for the variance and standard deviation. Assume that the variable is normally distributed...