Answer:
υ= 25
Step-by-step explanation:
IF we have two small independent samples from two normal populations with means μ1 and μ2 and standard deviations σ1 and σ 2 but unknown ,then the unbiased pooled or combined estimate of the common variance sigma square ha s student's t distribution with degrees of freedom given by
υ= n1+ n2- 2
In the given question
Sample A size= n1= 12
Sample B size = n2= 15
υ= 12+15-2
υ= 25
where
sp²= (n1-1) s1² + (n2-1) s2² / n1+n2-2
Answer:
4:18, 6:27, etc
Step-by-step explanation:
Basically, anything x 2 and x 9 would be equivalent as a ratio
A1 is the first term, in this case, A1 is 1
R is the ratio between adjacent numbers, in this case, R=3 because 3/1=3, 9/3=3, 27/9=3, 81/27=3
(-1,-13).....x = -1 and y = -13
y = 3x - 10y = -2x - 15
-13 = 3(-1) - 10(-13) = -2(-1) - 15...answer is B.
Answer: 54 flowers
Step-by-step explanation:
0.6 is 60% as a decimal
90 * 0.6 = 54
Thus, since 60% of 90 is 54 and 60% of the flowers are yellow, 54 flowers are yellow.