Question

you select two independent random samples from populations with means u1 and u2. suppose the sample mean for population 1 is 25 and σ1=3 and the sample mean for population is 20 and σ2=4. the 95% confidence interval for u1-u2 is (4.02,5.98). what common sample size, n, was used to obtain this interval?

Answer 1

Answers Goren, 2 population I population 41-25 5-20 - 4 23 Ny=h non Formula for confidence internal de to mean doffence CI = (x,-82) 12V A Y ne The 95% contodence interval, 4 valueis 1.96 Nowy (x-8) + 1.96/ 05 M Airen 95% confodenu Interal for meanditteunce Is (4.02, 598) Lownlimot de 402 Uppultust is sort CI = (x - x) ± 1.96 art sh = n₂ = h for common Camplesizin

D lony ito, n n Now, (X-8 1) - 1.9 * MM, < (8 - x) + 1.96mor subrotute X, X, 8, se valve an asore formula. (25-20) 1.91 31 741 r < M - My < (28-2014 196/034cyje o bora con n n 5-1.96 s ...1 - Mza 5+1.968 25 n Now, Lowa limot il s-1.26 1-44/4.02 0 Opper limot it St1.96/25 Ja q6 n solve equation do equations are can get ne value V 5-1.96/25 4.02 -2/

5-1.96 25 4.00 n -7.9625 YOLS n = -0.98 1961 25 0.98 n OrQ8 7.96 -Oos 25 = Coor = 0.25 0.25 25 n O. 25 25 n = 25 =100. 0.25 n=100 Common cample linen is Theutore, Required . LOD. n=100