Answer:
Step-by-step explanation:
Hello!
Your study variable is X: "number of ColorSmart-5000 that didn't need repairs after 5 years of use, in a sample of 390"
X~Bi (n;ρ)
ρ: population proportion of ColorSmart-5000 that didn't need repairs after 5 years of use. ρ = 0.95
n= 390
x= 303
sample proportion ^ρ: x/n = 303/390 = 0.776 ≅ 0.78
Applying the Central Limit Theorem you approximate the distribution of the sample proportion to normal to obtain the statistic to use.
You are asked to estimate the population proportion of televisions that didn't require repairs with a confidence interval, the formula is:
^ρ±
* √[(^ρ(1-^ρ))/n]
= 
= 2.58
0.78±2.58* √[(0.78(1-0.78))/390]
0.0541
[0.726;0.834]
With a confidence level of 99% you'd expect that the interval [0.726;0.834] contains the true value of the proportion of ColorSmart-5000 that didn't need repairs after 5 years of use.
I hope it helps!
Answer:it’s going to be b
Step-by-step explanation:
Direct Proportion functions look like this:
y=kx
'k' is the constant of proportionality and in this case its 7.5 or 15/2.
--------------------------------------------
When x=1, y=7.5
When x=2, y=15
When x=3, y=22.5
Therefore y is directly proportional to x.
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DIRECT PROPORTION EXPLAINED:
Say a football costs £7.50. If you buy one football you'll have to pay out £7.50, but if you you buy two footballs you'll have to pay out £15.00. Therefore the cost of the football(s) is directly proportional to the amount of footballs you buy. C=cost, f=football(s) and C<span>∝f, therefore C=kf, but as k=7.5, C=7.5f.
INVERSE PROPORTION EXPLAINED:
If it were to take 8 hours for one bricklayer to set up a wall, how long would it take for two bricklayers to set up a wall? The answer in this case would be 4 hours.
T=time to set up a wall
b=bricklayer(s)
Therefore T</span><span>∝1/b, and T=k/b. In this case k=8 so T=8/b.
When b=1, T=8.
When b=2, T=4.
We'd say that the time it would take for bricklayers to set up a wall would be inversely proportional to the amount of bricklayers available.</span>
Answer:
4.F(x) > 0 over the intervals (-0.7, 0.76) and (0.76, ∞).
Step-by-step explanation:
Girls: 81
boys: 75
4x +6 = 156
4x = 150
x = 37.5
2x = 75
girls: 75 + 6
boys: x
