Answer:
20 +/- $6.74
= ( $13.26, $26.74)
The 90% confidence interval for the difference in average amounts spent on textbooks (math majors - English majors) is ( $13.26, $26.74)
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.
x1-x2 +/- margin of error
x1-x2 +/- z(√(r1^2/n1 + r2^2/n2)
Given that;
Mean x1 = $200
x2 = $180
Standard deviation r1 = $22.50
r2 = $18.30
Number of samples n1 = 60
n2 = 40
Confidence interval = 90%
z(at 90% confidence) = 1.645
Substituting the values we have;
$200-$180 +/-1.645(√(22.5^2/60 +18.3^2/40)
$20 +/- 6.744449847374
$20 +/- $6.74
= ( $13.26, $26.74)
The 90% confidence interval for the difference in average amounts spent on textbooks (math majors - English majors) is ( $13.26, $26.74)
Answer: 5
Step-by-step explanation:20 times .25
Answer:
Given below
Step-by-step explanation:
M is Mikey and B is Betty in,
Current ages:
M= x
B= 3x (cuz she is 3 times older)
After 5 years
M= x+5
B= 3x+5 (5 years added to present age)
It says the ages of Betty after 5 years (3x+5) will be twice as much as Mikey (2(X+5))
So,
3x+5 = 2(x+5)
3x+5 = 2x+10
3x -2x = 10-5
x = 5
Therefore,
The current ages are
Betty : 3x = 3*5 = 15
Mikey: 5 (x)
You can verify by checking with the criterias or clues given in the question.. hope this helps..mark as brainiest if this was helpful:)
Answer:
Cluster sampling
Step-by-step explanation:
Cluster sampling refers to the sampling that is used in market analysis. It is used when a researcher can not obtain information as a whole for the population but may obtain information through the groups or clusters
In the given case since andrew divides the residents through regions so this reflected the cluster sampling method
Answer:
B. 56.52
Step-by-step explanation:
C = 2πr
- C = circumference
- r = radius of the circle
- the constant pi = 3.14
Therefore,
56.52 = 2(3.14)(9)
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