The direct variation between x and y may be written as,
y = kx
where k is the constant of variation. From the first set of values of the variables,
12 = k(8)
the value of k is 1.5. Substituting the next set to the same equation,
y = 1.5(14)
The value of y is 21.
Answer:
x=2.50
Step-by-step explanation:
But I am not sure if its positive or negative.
Answer:
(22.12, 27.48)
Step-by-step explanation:
Given : Significance level : 
Sample size : n= 8 , which is a small sample (n<30), so we use t-test.
Critical values using t-distribution: 
Sample mean : 
Standard deviation : 
The confidence interval for population means is given by :-
i.e. 
Hence, the 95% confidence interval, assuming the times are normally distributed.= (22.12, 27.48)
Mean is average so you sum up all 4 numbers and divide by 4. Answer is 27.6725 or rounded 27.67
Have a nice day. Hope this helps.
Answer:
Step-by-step explanation:
We want to determine a 90% confidence interval for the true population mean textbook weight.
Number of sample, n = 22
Mean, u = 64 ounces
Standard deviation, s = 5.1 ounces
For a confidence level of 90%, the corresponding z value is 1.645. This is determined from the normal distribution table.
We will apply the formula
Confidence interval
= mean ± z ×standard deviation/√n
It becomes
64 ± 1.645 × 5.1/√22
= 64 ± 1.645 × 1.087
= 64 ± 1.788
The lower end of the confidence interval is 64 - 1.788 = 62.21 ounces
The upper end of the confidence interval is 64 + 1.788 = 65.79 ounces
Therefore, with 90% confidence interval, the true population mean textbook weight is between 62.21 ounces and 65.79 ounces
