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Answer:
99% confidence interval for the population average examination score is between a lower limit of 69.2872 and an upper limit of 82.7128.
Step-by-step explanation:
Confidence interval = mean +/- margin of error (E)
mean = 76
variance = 144
sd = sqrt(variance) = sqrt(144) = 12
n = 25
degree of freedom (df) = n - 1 = 25 - 1 = 24
confidence level (C) = 99% = 0.99
significance level = 1 - C = 1 - 0.99 = 0.01 = 1%
t-value corresponding to 24 df and 1% significance level is 2.797
E = t×sd/√n = 2.797×12/√25 = 6.7128
Lower limit = mean - E = 76 - 6.7128 = 69.2872
Upper limit = mean + E = 76 + 6.7128 = 82.7128
99% confidence interval is (69.2872, 82.7128)
Answer:
7. Mean = 48
Median = 47.5
Mode = 72
Range = 66
8. Mean= 59.625
Median = 61
Mode = 90
Range = 79
9. Mean = 31.57
Median = 32
Mode = 46
Range = 34
10. Mean = 42.11
Median = 36
Mode = 51
Range = 51
Step-by-step explanation:
Mean is the average. Mode is the number that appears the most. Median is the middle number. Range is the biggest number minus the smallest number.
Hope this helps.
This is a quadratic equation, which is also a polynomial. Polynomials all have the domain (-infinity, +infinity).
As for the range: You can see from the graph that the smallest y-value is -2. Thus, the range is [-2, infinity).
