Divide the total number correct, by the total number of questions on the test. 42/60=70%
Answer:
$393.50+/-$19.72
= ( $373.78, $413.22)
Therefore, the 95% confidence interval (a,b) = ($373.78, $413.22)
Step-by-step explanation:
Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.
The confidence interval of a statistical data can be written as.
x+/-zr/√n
Given that;
Mean x = $393.50
Standard deviation r = $50.30
Number of samples n = 25
Confidence interval = 95%
z value(at 95% confidence) = 1.96
Substituting the values we have;
$393.50+/-1.96($50.30/√25)
$393.50+/-1.96($10.06)
$393.50+/-$19.7176
$393.50+/-$19.72
= ( $373.78, $413.22)
Therefore, the 95% confidence interval (a,b) = ($373.78, $413.22)
The correct answer is Choice B: 720.
To solve this, you have to use the Fundamental Counting Principal. You find the total number of options for each of the digits, then multiply them together.
For the first one, there are 10 options, then 9 options and finally 8 options.
10 x 9 x 8 = 720
3:1 =300%
2:3:5 =50%
1:4 =25%
1:2:5 =62.5%
1) 2x + 3y = 12 -> 3y = -2x +12 -> y = -2/3x + 4
2) 4y - 7x = 16 -> 4y = 7x + 16 -> y = 7/4x + 4