continuous variable in frequency distribution

A sample of 30 RAM chips was tested for the average access time. The standard deviation was found to be 2 nanosec. Find the 90% confidence interval for the true standard deviation. Assume that the variable is normally distributed. => between 1.7 and 2.6 or between 1.6 and 2.5 or..

The daily water usage (in gallons per person per day) of 10 families of a colony has a variance of 286. Find the 90% confidence interval for the variance and standard deviation. Assume that the variable is normally distributed. => 152 < σ 2 < 774 ; 12 < σ &l..

Edward took 16 mock tests. In 3 of the tests, his score is average. In 2 of the tests, his score is above average and in 5 of the tests his score is below average. In the remaining 6 tests his score is good. Which frequency distribution is appropriate for his test scores? => Tab..

The average age of media reporters worldwide is 35 years with a standard deviation of 6 years. If a media channel employs 50 media reporters, then what is the probability that their mean age is above 38 years? Assume that the variable is normally distributed. => 0.1% or 1% or 0...

The average age of employees in a firm is 35 years. Assume the variable is normally distributed. If the standard deviation is 3 years, then find the probability that the age of a randomly selected employee will be greater than 38 years. => 15.87% or 65.87% or 34.13% or 94.13%..

The average age of the employees in an organization is 34 years. Assume the variable is normally distributed and the standard deviation is 4 years. If 30 employees are selected at random, then find the probability that the mean age of the employees is greater than 32 years. => 0..

The average protein content in different types of nuts is 20 g, and the standard deviation is 5 g. Assume the variable is normally distributed. If a sample of 16 nuts are selected, then find the probability that the mean of the sample will be greater than 22 g. => 65.54% or 34.4..

The university authorities wanted to estimate the average age of the students in their university by taking a random sample of 25 students. The standard deviation was found to be 3 years. Find the 95% confidence interval for the variance (σ 2 ) and standard deviation (σ). Assume that th..

An automobile parts supplier wants to know how long car owners plan to keep their cars with them. A random sample of 20 car owners results in a standard deviation of 3.7 years. Find a 95% confidence interval for the variance and standard deviation. Assume that the variable is normally ..

Identify the discrepancy in the frequency distribution. Class Frequency 15 - 19 2 19 - 23 3 23 - 27 1 27 - 31 6 31 - 35 4 => The class width should be more than 5 and it should be an odd number. or The class width should be more that 5, the classes must be mutually exc..