Answer:
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Step-by-step explanation:
Answer:
Sample mean = 7.1
Margin of error = 0.465
Step-by-step explanation:
Formula for confidence interval is;
CI = x¯ ± zE
Where;
x¯ is sample mean
z is critical value at confidence level
E is margin of error.
z for 99% Cl is 2.58
We are told the CI is 5.9 to 8.3.
Thus;
5.9 = x¯ - 2.58E - - - - (1)
8.3 = x¯ + 2.58E - - - - (2)
Add both equations together to get;
14.2 = 2x¯
x¯ = 14.2/2
x¯ = 7.1
Put 7.1 for x¯ in eq 1 to get;
5.9 = 7.1 - 2.58E
7.1 - 5.9 = 2.58E
E = 1.2/2.58
E = 0.465
Answer:
68% of an investment earning a return between 6 percent and 24 percent.
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 15
Standard deviation = 9
How likely is it to earn a return between 6 percent and 24 percent?
6 = 15 - 1*9
6 is one standard deviation below the mean
24 = 15 + 1*9
24 is one standard deviation above the mean
By the empirical rule, there is a 68% of an investment earning a return between 6 percent and 24 percent.
Answer:
eng pls
Step-by-step explanation: