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:
A. The temperature outisde and the number of people swimming at the beach.
Step-by-step explanation:
As the temperature decreases the number of people swimming will also decrease. This will create a negative correlation between the two factors.
Tbe question doesn't state the number of days he walked to school out of 20 school days in the
Month of February.
Answer:
Kindly check explanation
Step-by-step explanation:
To. Obtain the fractional representayion for the number of days he walked to school ;
Let the number of days he walked to school = 10 (this is an hypothesized value)
Number of school days in February = 20
Fraction = 10 /20 = 0.5
The percentage of times walked to school : multiply the fraction obtained above by 100%
0.5 * 100% = 50%
Just put the desired value and proceed uSing the steps described above.
