Answer:
The 90% confidence interval for the mean test score is between 77.29 and 85.71.
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 25 - 1 = 24
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 24 degrees of freedom(y-axis) and a confidence level of 
. So we have T = 2.064
The margin of error is:
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 81.5 - 4.21 = 77.29
The upper end of the interval is the sample mean added to M. So it is 81.5 + 4.21 = 85.71.
The 90% confidence interval for the mean test score is between 77.29 and 85.71.
Step-by-step explanation:
a) 24.7×52.3=1291.81
On rounding off to 3 significant digits we get
1290
b)
=31.304951
On rounding off to 5 significant figures we get
=31.305
c)
![\sqrt[3]{78} = 4.27265](https://tex.z-dn.net/?f=%20%5Csqrt%5B3%5D%7B78%7D%20%20%3D%204.27265)
On rounding off to 2 significant figures we get
=4.3
Hence required answers
a)1290
b)31.305
c)4.3
I hope it helped you
9514 1404 393
Answer:
(a) 26 units
Step-by-step explanation:
The left-side vertical line extends from y = -3 to y = +3, so is 3-(-3) = 6 units long.
The bottom side horizontal line extends from x = -5 to x = 2, so is 2 -(-5) - 7 units long.
The sum of these two sides is 6 + 7 = 13 units. These two sides make up half of the perimeter, which is the total length of all four sides.
The perimeter is 2 × 13 units = 26 units.
Answer:
a/b = c/d --> d = b*c/a
d is the forth proportional
a) d = 2*3/1 = 6
b) d = 3*4/0.5 = 24
c) d = b*5/a = 5*b/a
-15x=-4x
We know that adding zero wouldn’t change the value
-15x=-4x+0
Now we can add 4x (since that’s the opposite of the negative sign) to the other side
-11x=0
0 divided by 11 is 0
x=0
