EASY POINTS:
2 answers:
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Answer:
Step-by-step explanation:
Given that n =30, x bar = 375 and sigma = 81
Normal distribution is assumed and population std dev is known
Hence z critical values can be used.
For 95% Z critical=1.96
Margin of error =
Confidence interval = 375±29
=(346,404)
B) 99% confidence
Margin of error = 2.59*Std error =38
Confidence interval = 375±38
=(337, 413)
C) For 90%
Margin of error = 20
Std error = 20/1.645 = 12.158
Sample size
Atleast 44 people should be sample size.
Answer:
There are 60 boys and 80 girls in Franklin School.
Step-by-step explanation:
"franklin school has 3 boys for every 4 girls in the fifth grade." means that the ratio of boys to girls is: 3:4
It can also be written as 3/4
Also given
Total number of students: 140
We will use ratios to find the number of boys and girls in shool.
First of all, we have to calculate the sum of ratio which is: 3+4 = 7
Let b be the number of boys and g be the number of girls
Then
Hence,
There are 60 boys and 80 girls in Franklin School.