Answer:
81 samples
Step-by-step explanation:
According to the empirical rule :
Possible values of the sample mean is within 3 standard deviations of the population mean :
μ ± 3 sd(x) ; sd(x) = standard deviation of sampling distribution.
3 * sd(x) = 1
sd(x) = 1/3
Recall:
Standard deviation of sampling distribution, sd(x)
sd(x) = σ / sqrt(n)
1/3 = 3 / sqrt(n)
Square both sides
1/9 = 9/n
Cross multiply :
n * 1 = 9 * 9
n = 81
Answer:
<u><em>y=7 </em></u><u>number of hours at grocery store</u>
<u><em>x=18 </em></u><u>number of hours at baby- sitting</u>
Step-by-step explanation:
According to the information provided.
x is number of hours at baby- sitting
y is number of hours at grocery store
total number of hours worked
<em>1) </em><em>x+y =25</em>
total earn in a week
<em>2) </em><em>x*$6 + y* $9 = $171</em>
<em />
<em>from equation 1</em>
x+y=25
x= 25-y
<em>we place the above derived equation in equation 2 </em>
x*$6 + y* $9 = $171
(25-y)*$6 + y* $9 = $171
(25*6) -6y +9y =171
150+3y=171
3y=171-150
3y=21
<u><em>y=7 </em></u><u>number of hours at grocery store</u>
x= 25-y
x= 25-7
<u><em>x=18 </em></u><u>number of hours at baby- sitting</u>
The product of x and 6: 6(x)
is at least -17: ≥ 17
6x ≥ 17 is your answer
hope this helps
3 Metres; because for each 100 centimetres there is one metre. With centi- being the prefix for 10^-2 in the metric system.
