Answer:
The smallest sample size n that will guarantee at least a 90% chance of the sample mean income being within $500 of the population mean income is 48.
Step-by-step explanation:
The complete question is:
The mean salary of people living in a certain city is $37,500 with a standard deviation of $2,103. A sample of n people will be selected at random from those living in the city. Find the smallest sample size n that will guarantee at least a 90% chance of the sample mean income being within $500 of the population mean income. Round your answer up to the next largest whole number.
Solution:
The (1 - <em>α</em>)% confidence interval for population mean is:
The margin of error for this interval is:
The critical value of <em>z</em> for 90% confidence level is:
<em>z</em> = 1.645
Compute the required sample size as follows:
![n=[\frac{z_{\alpha/2}\cdot\sigma}{MOE}]^{2}\\\\=[\frac{1.645\times 2103}{500}]^{2}\\\\=47.8707620769\\\\\approx 48](https://tex.z-dn.net/?f=n%3D%5B%5Cfrac%7Bz_%7B%5Calpha%2F2%7D%5Ccdot%5Csigma%7D%7BMOE%7D%5D%5E%7B2%7D%5C%5C%5C%5C%3D%5B%5Cfrac%7B1.645%5Ctimes%202103%7D%7B500%7D%5D%5E%7B2%7D%5C%5C%5C%5C%3D47.8707620769%5C%5C%5C%5C%5Capprox%2048)
Thus, the smallest sample size n that will guarantee at least a 90% chance of the sample mean income being within $500 of the population mean income is 48.
Take a more clear picture then I will help you
Answer:
M = 4.33885225095
Step-by-step explanation:
Area of the square ABFE = 10² = 100
M = 100 - (2P + Q)
Let’s calculate 2P + Q :
The area 2P + Q = area ΔABC + area of sector ACE + area of sector BCF
Note :
ΔABC is an equilateral triangle
m∠CBF = m∠CAE = 30°
area ΔABC = (CG × AB)÷2 = (8.660254037844×10)÷2 = 43.30127018922
CG = √(10^2 - 5^2)=8.660254037844 (Pythagorean theorem)
area of sector BCF = area ΔACE = 100π ÷ 12 = (8.333333333333)π
then
Area 2P + Q = area ΔABC + area sector ACE + area sector BCF
= 43.30127018922+(100÷12)π+(100÷12)π
= 43.30127018922+ (8.333333333333)π + (8.333333333333)π
= 95.66114774905
Conclusion:
M = 100 - (2P + Q) = 100-95.66114774905 = 4.33885225095
Answer:
5y+3x=123
Step-by-step explanation:
(x1,y1)=(1,24), m=-0.6
y-y1=m(x-x1)
y-24=-0.6(x-1)
y-24=-6/10(x-1)
10(y-24)=-6(x-1)
10y-240=-6x+6
10y+6x=6+240
10y+6x=246
divide by through by 2
5y+3x=123
9514 1404 393
Answer:
see attached
Step-by-step explanation:
I like to use a spreadsheet for repetitive calculations. The distances are computed from the distance formula:
d = √((x2 -x1)^2 +(y2 -y1)^2)
The results are shown in the second attachment. The drawing in the first attachment has the lengths rounded to the nearest tenth.
