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)
3/4 * 5/7 = 15/28 or 0.5357
Answer:
1/7
Step-by-step explanation:
Since we do not know the number let us use the alphabet A to represent the unknown number
A × 1/3= 1/21
A/3= 1/21
Cross multiply both sides
A×21= 3×1
21A= 3
Divide both sides by the coefficient of A which is 21
21A/21=3/21
A=1/7
Hence the unknown number is 1/7
Answer: Option 'B' and 'C' are correct.
Step-by-step explanation:
Since we know that irrational numbers are those real number which cannot be written in 
form.
Rational numbers are those real numbers which can be written in form.
Inverse property of multiplication is that property in which we write a number in reciprocal form .
Whole numbers starts from 0 and Natural numbers start from 1 and Integers contain both positive and negative numbers.
Hence, 
belongs to rational numbers sets and inverse property of multiplication sets.
Therefore, Option 'B' and 'C' are correct.
