Lucille has a collection of more than 500 songs on her phone that have a mean duration of 215 seconds
and a standard deviation of 35 seconds. Suppose that every week she makes a playlist by taking an SRS of
49 of these songs, and we calculate the sample mean duration of the songs in each sample.

5

Step-by-step explanation:

The sample mean is given by dividing the standard deviation by the squareroot of SRS

Given standard deviation of 35 and SRS of 49, we know that the squareroot of 49 is 7 ie √49=7

By substituting the given values we can obtain the sample mean as follows.

sample mean=35/√49=35/7=5

The sample mean for the given question is hence 5

incomplete question. how do you expect anyone to you when you do not post the question in its entirety?

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116