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)
Without speeding up it would take 5 1/3 seconds.. not sure if it speeds up in the question?
Answer:
2
Step-by-step explanation:
there is 2: 3<u> 1 </u>
4
the answer is 153.86 ft squared
= the formula for the area of a circle is A=πr2
= area = pi x radius squared
= the radius is 7 feet, square that to get 49
= multiply 49 by pi to get the area: 153.86 square feet
153.86 ft squared
Answer:
B
Step-by-step explanation:
Hope this helps you out! :)