4*7=28
5y=28
divide 5 to 28
y=5.6
Answer:
Step-by-step explanation:
Given that X, the number of square feet per house is N(mean, 137)
Sample size = 19
Sample mean x bar =1350 sq ft
Since population std dev is given,
std error of sample = 
Since sample size is small, t critical value can be used
df = 18
t value for 80% two tailed = 1.333
Margin of error = ±1.333(std error) = ±
Confidence interval = sample mean ±margin of error
= 
You have to turn the number or ratio and simplified the number and put it in to the chart like the norm number
.