Please help! IXL math problem
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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!
The lottery game is an illustration of probability
- The total number of different selections is 1000
- The probability of winning is 0.001
- The net profit of winning is $262.82
- The expected earning is -$1.156
Each of the three selections can be any of the 1o digits 0 - 9.
So, the total number of different selections is:
Only one of the 1000 selections can win.
So, the probability of winning is:
The stake amount is given as $1.42, and the earnings per game is given as $264.25.
So, the net profit is:
Net = $264.25 - $1.42
Net = $262.82
<h3>The expected winnings</h3>This is calculated as:
So, we have:
Hence, the expected earning is -$1.156
Read more about probability at: