<span>A has earned twice as much as B so: A=2B
B has averaged 50% more than C so: B=C+0.5C
Combined is 220K, So A+B+C=220,000
The last equation can be re-written as:
2B+1.5C+C=220K
AND since A=2B, it can be rewritten again as:
3C+1.5C+C=220K
Now you can get C
finally, since B=1.5C you can get B, then to get the average, just divide that by 3 (years) and you should be done.
So B = 60000 for 3 years</span>
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Have a beautiful and joyful day ahead
Thanks for points..
Answer: -3/5
Step-by-step explanation:
Answer:
Type I error
Step-by-step explanation:
A type I error occurs if the null hypothesis is rejected when it is actually true.
Type I Type II
Reject null when true Fail to reject null when not true
Null hypothesis: ∪ = 30%
Alternative hypothesis: ∪ > 30%
The researchers concluded that more than 30% of first-grade students at this school have entered the concrete operational stage of development and they rejected the null hypothesis.
However, a census actually found that in the population of all first graders at this school, only 28% have entered the concrete operational stage.
A type I error has been made because in actuality the null hypothesis was true but was rejected.
Answer:
95% Confidence interval for the variance:
95% Confidence interval for the standard deviation:
Step-by-step explanation:
We have to calculate a 95% confidence interval for the standard deviation σ and the variance σ².
The sample, of size n=8, has a standard deviation of s=2.89 miles.
Then, the variance of the sample is
The confidence interval for the variance is:
The critical values for the Chi-square distribution for a 95% confidence (α=0.05) interval are:
Then, the confidence interval can be calculated as:
If we calculate the square root for each bound we will have the confidence interval for the standard deviation:
