Answer:
p=0.063
Step-by-step explanation:
Let X be number of the certain brand of jelly beans that are made so that each package contains about the same number of beans.
X is N(375, 8)
YOu are collecting a sample size of
n = 8
Findings from the sample
(Left tailed test at 5% level)
Since sample size is small though sigma is known we use Z test, since norm
Mean difference = -5
Std error =
Test statistic t = mean diference / std error =
df = n-1 =5
p value = 0.063
Answer:
The mean of 25 students is 17.6
Step-by-step explanation:
The formula of the mean (average) is mean (average) = , where S is the sum of the data, and N is the number of the data
∵ The average marks of the first 10 students are 17
- That means the mean is 17 and the number of students is 10
∴ Average = 17
∴ N = 10
∵ Average =
- Substitute average by 17 and N by 10
∴ 17 =
- Multiply both sides by 10
∴ 170 = S
∴ The sum of the marks of the first 10 students is 170
∵ The average of the next 15 students is 18
∴ Average = 18
∴ N = 15
- Substitute average by 18 and N by 15
∴ 18 =
- Multiply both sides by 15
∴ 270 = S
∴ The sum of the marks of the next 15 students is 270
Now to find the mean of 25 students and the two sums and divide the answer by 25
∵ S = 170 + 270
∴ S = 440
∵ N = 25
∴ Mean =
∴ Mean = 17.6
The mean of 25 students is 17.6