Answer:
12 inches
Step-by-step explanation:
A=0.5bh
A=0.5xh
60=0.5*10*x
60=5x
5x=60
x=12
Step-by-step explanation:
10. 8a - 12b
11. d^8
12. 3y^3
13. 4a+b
14. 11x-3
15. 2a^2+2ab
16. 2x^3+x
17. 4(a+2)
18. 3m(m-3)
Answer:
456 students
Step-by-step explanation:
In order to find 95% of the 480 students, you can set up the equation below:
x * 100 = 480 * 95
x = 45600 / 100 = 456
95% of 480 students is 456 students.
Answer:
the population means are known the population variances are assumed equal but unknown
Step-by-step explanation:
If σ1= σ2 (= σ) but unknown , then the biased pooled or combined estimate of the common variance σ² ( the term common variance means that each population has the same variance ) is given by
Sp²= (n1-1) s1² + (n2-1) s2²/ n1+ n2- 2
So first assumption is correct.
When the population variances are assumed unequal and unknown
If σ1 ≠ σ2 but unknown
we use the sample estimates s1 and s2 to compute the standard error of the difference between the means.
S(x1`- x2`) = √s1²/ n1 + s2²/n2
So this is does not apply here.