Answer:
(115.2642, 222.7358).
Step-by-step explanation:
Given data:
type A: n_1=60, xbar_1=1827, s_1=168
type B: n_2=180, xbar_2=1658, s_2=225
n_1 = sample size 1, n_2= sample size 2
xbar_1, xbar_2 are mean life of sample 1 and 2 respectively. Similarly, s_1 and s_2 are standard deviation of 1,2.
a=0.05, |Z(0.025)|=1.96 (from the standard normal table)
So 95% CI is
(xbar_1 -xbar_2) ± Z×√[s1^2/n1 + s2^2/n2]
=(1827-1658) ± 1.96×sqrt(168^2/60 + 225^2/180)
= (115.2642, 222.7358).
Answer:
y-7 = 4(x+9)
Step-by-step explanation:
Point slope form is
y-y1 = m(x-x1)
where m is the slope and (x1,y1) is the point
y-7 = 4(x--9)
y-7 = 4(x+9)
Answer:
the answer is -5/2
hope it helps you mate..
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Answer: 
Step-by-step explanation:
For this exercise it is important to remember the following:
The constant of proportionality, which is represented as "k", describe the constant ratio of two quantities that are proportional (the independent and dependent variables).
In this case we know that the independent quantity represents the total members of the band and the dependent quantity represents the woodwind members of the band.
Since the band consists of 3 woodwinds for every 7 members of the band, we can conclude that the constant of proportionality for this relationship is:

Answer:
The percentage of the students scored higher than 89% is 15.87%
Step-by-step explanation:
we are given
The average test scores for a particular test in algebra was 84
so, mean is 84

a standard deviation of 5
so,

we have
x=89
now, we can use z-score formula

now, we can plug values


now, we can use calculator
and we get

So,
The percentage of the students scored higher than 89% is 15.87%