The lifetime of all the batteries produced by a certain company in a year have a distribution that is symmetric about the mean m. If the distribution has a standard deviation of d, what percent of the distribution is greater than m+d?
(1) 68 percent of the distribution lies in the interval from m-d to m+d, inclusive
(2) 16 percent of the distribution is less than m-d
OA D
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The lifetime of all the batteries produced by a certain comp
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What percentage of the distribution is greater than (m+d)
Statement 1
68% of the distribution lies in the interval from (m-d) to (m+d) inclusive
100% - 68% = 32% is less than (m-d) and more than (m+d)
As distribution is symmetric about the mean , the exactly half of 32% or 16% would be more than (m+d)
Statement 1 is SUFFICIENT.
Statement 2
16% of the distribution is less than (m-d)
Since distribution is symmetric abut the mean, then exactly 16% will be greater than (m+d).
Statement 2 is SUFFICIENT.
Both statement alone are SUFFICIENT.
$$answer\ is\ Option\ \ D$$
Statement 1
68% of the distribution lies in the interval from (m-d) to (m+d) inclusive
100% - 68% = 32% is less than (m-d) and more than (m+d)
As distribution is symmetric about the mean , the exactly half of 32% or 16% would be more than (m+d)
Statement 1 is SUFFICIENT.
Statement 2
16% of the distribution is less than (m-d)
Since distribution is symmetric abut the mean, then exactly 16% will be greater than (m+d).
Statement 2 is SUFFICIENT.
Both statement alone are SUFFICIENT.
$$answer\ is\ Option\ \ D$$
