what are class intervals

A study of 50 basket ball players showed that their scoring average is 15.8 points per game. The 90% confidence interval of the mean score for all players is between 14.1 and 17.5. Find the 90% confidence interval of the mean score(μ) if 100 players are considered instead of ..

The stem and leaf plot shows the number of chocolates with the students of a class. How many data values are there in all in both the intervals 20 to 29 and 40 to 49? => 11 or 12 or 10 or 9..

From the stem-and-leaf plot, find how many data values are less than 94, from the intervals 80 - 89, 90 - 99, 100 - 109 and 110 - 119. => 5 or 4 or 6 or 7..

Use the stem-and-leaf plot to find the number of data items in the interval 20 - 69. => 18 or 14 or 20 or 17..

Approximate the area of the region under the curve over the interval [0, 6] by using LRAM. [Use 11 rectangles.] => 25.75 square units or 23.345 square units or 24.35 square units or 21 square units..

Approximate the area of the region below the graph over the interval [-2, 2] by using PRAM. [Use 8 rectangles.] => 21.315 square units or 16.248 square units or 116 square units or 13.5 square units..

Approximate the area of the region below the graph over the interval [0, 2] by using LRAM.[Use 7 rectangles.] => 18 cm 2 or 9 cm 2 or 8.275 cm 2 or 5.786 cm 2..

Approximate the area of the region below the graph over the interval [0, 1] by using PRAM. [Use 4 rectangles.] => 1.0125 cm 2 or 3.0125 cm 2 or 0.25625 cm 2 or 4.0125 cm 2..

In a random sample of 25 trees, the variance in height was found to be 6.9. Find the 95% confidence interval for the standard deviation. Assume that the variable is normally distributed. => between 4.9 and 13.7 or between 4.2 and 13.4 or between 5.5 and 14.1 or between 5.5 and 13.4..

A survey of 156 people showed that 104 go for a brisk walk daily. Find the 99% confidence interval of the true proportion of people who go for a brisk walk. => 57.3% < p < 76.7% or 63.2% < p < 70.8% or 66.6% < p < 67.4% or 66% < p < 70%..