Answer: 
Step-by-step explanation:
The confidence interval for population mean is given by :-

Given : Sample size : n= 35 , large sample (n>30)
Mean difference : 
Standard deviation : 
Significance level : 
Critical value : 
Now, the 99.9% confidence interval for the mean difference between the marks scored last week and marks scored this week by all the students will be :-

Hence, the 99.9% confidence interval for the mean difference between the marks scored last week and marks scored this week by all the students = 
54-15=39
if you want to check your answer you add 39+15=54
Answer:
x ≈ 0.290640965127
Step-by-step explanation:
y subtracting the right side of the equation, we get a function that is zero at a real solution for x. The only x-intercept is at approximately 0.290640965127.
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The graph shows the x-intercept to be 0.2906. The value above was obtained by Newton's method iteration. The roots of this cubic will all be irrational.
Answer:
13/15 > 4/5 is a true stament.
Step-by-step explanation:
The left side is 0.86 repeating turned into a decimal. which means 0.86 is greater than the right which the right is 0.8 turned into a decimal. which in this case this means that the given stament is always true.