what are class intervals

A random sample of 100 similar iron bars manufactured at a factory had a mean diameter of 6.43 mm and a variance of 0.032 mm 2 . Find 95% confidence interval and 99% confidence interval. Which interval is smaller? => (6.40, 6.47) and (6.38, 6.48) and 95% or (6.395, 6.4..

The 95% confidence interval for the mean weight of a sack of potatoes is between 4.92 and 5.08. If a random sample of 32 sacks was used to determine this interval, what was the standard deviation? => 0.04 or 0.16 or 3.92 or 0.23..

The 95% confidence interval for the mean number of sheets of paper in a ream is between 452.76 and 447.24. If the standard deviation is 10 papers, find the size of the random sample that was used to determine this interval. => 5.52 or 50 or 1.41 or 7.09..

What would be the sampling interval, if a systematic sample of 500 students has to be carried out in a university with an enrolled population of 10,000? => 50 or 20 or 1000 or 500..

How many leaves are there in the interval 20 - 32 in the stem-and-leaf plot? => 6 or 7 or 5 or 4..

The bar graph displays the number of customers visitng a shopping mall in Sheldon in a day. At which time interval were there the maximum number of customers at the mall? => 7 - 10 P.M. or 10 - 12 P.M. or 2 - 7 P.M. or None of the above..

Convert interval notation [- 2, 4) to inequality notation. => 2 ≤ x ≤ 4 or - 2 ≤ x < 4 or - 2 < x < 4 or - 2 ≤ x ≤ 4..

Convert interval notation [- 4, 6) to inequality notation. => - 4 ≤ x ≤ 6 or - 4 < x < 6 or 4 ≤ x ≤ 6 or - 4 ≤ x < 6..

A survey of 120 families showed that at least 78 had a computer at home. Find the 99% confidence interval of the true proportion of families who own a home computer. => 64.5% < p < 65.5% or 5.38% < p < 7.62% or 53.8% < p < 76.2% or 60.6% < p < 69.4%..

90% confidence interval of a population mean(μ) worked out on a sample size of 50 is, 50 < μ < 56. What is the likely 90% confidence interval of the mean of the same population worked out on a sample size of 100? => 25 < μ < 28 or 51 < μ <..