csat-suneung· South-Korea· csat__math-science3 marks
A factory produces table tennis balls. When dropped from a certain height onto a steel floor, the height to which the table tennis ball bounces follows a normal distribution. From the table tennis balls produced by this factory, 100 balls were randomly sampled and the bounce height was measured, resulting in a mean of 245 and a standard deviation of 20. What is the number of integers in the 95\% confidence interval for the mean bounce height of all table tennis balls produced by this factory? (Here, the unit of height is mm, and when $Z$ follows the standard normal distribution, $\mathrm { P } ( 0 \leqq Z \leqq 1.96 ) = 0.4750$.) [3 points] (1) 5 (2) 6 (3) 7 (4) 8 (5) 9
A factory produces table tennis balls. When dropped from a certain height onto a steel floor, the height to which the table tennis ball bounces follows a normal distribution. From the table tennis balls produced by this factory, 100 balls were randomly sampled and the bounce height was measured, resulting in a mean of 245 and a standard deviation of 20.
What is the number of integers in the 95\% confidence interval for the mean bounce height of all table tennis balls produced by this factory?
(Here, the unit of height is mm, and when $Z$ follows the standard normal distribution, $\mathrm { P } ( 0 \leqq Z \leqq 1.96 ) = 0.4750$.) [3 points]\\
(1) 5\\
(2) 6\\
(3) 7\\
(4) 8\\
(5) 9