Answer:
For a sample size of 10, the t-value is about 3.25 (from tables) at a 99% confidence interval.
Explanation:
When the standard deviation for the population is not known, the confidence interval estimate for the population mean is performed with the Student's t-distribution.
The confidence interval for the mean is calculated as
![(\Bar{x}- t\frac{s}{\sqrt{n}} , \, \Bar{x}+ t\frac{s}{\sqrt{n}}](https://tex.z-dn.net/?f=%28%5CBar%7Bx%7D-%20t%5Cfrac%7Bs%7D%7B%5Csqrt%7Bn%7D%7D%20%2C%20%5C%2C%20%5CBar%7Bx%7D%2B%20t%5Cfrac%7Bs%7D%7B%5Csqrt%7Bn%7D%7D%20)
where
![\Bar{x}](https://tex.z-dn.net/?f=%5CBar%7Bx%7D)
= sample mean,
s = sample standard deviation,
t = t-value (provided in tables),
n = sample size.
When reading the t-value, (n-1) is called the df or degrees of freedom.
Answer: 242 in²
All the work is shown in the picture.
The product of side length and altitude is area. The area remains the same regardless of how you measure it.
From the first side and altitude,
.. area = side*altitude = (4.2 cm)*(3.6 cm) = 15.12 cm^2
From the second side and altitude
.. area = side*altitude
.. 15.12 cm^2 = side*(2.4 cm)
.. side = (15.12 cm^2)/(2.4 cm) = 6.3 cm
The perimeter is the sum of the measures of all sides. Opposite sides are of equal measure.
.. perimeter = 2*(4.2 cm +6.3 cm) = 21.0 cm