Answer:
(15,595, 16,805)
Step-by-step explanation:
We have to:
m = 16.2, sd = 3.75, n = 150
m is the mean, sd is the standard deviation and n is the sample size.
the degree of freedom would be:
n - 1 = 150 - 1 = 149
df = 149
at 95% confidence level the t is:
alpha = 1 - 95% = 1 - 0.95 = 0.05
alpha / 2 = 0.05 / 2 = 0.025
now well for t alpha / 2 (0.025) and df (149) = t = 1,976
the margin of error = E = t * sd / (n ^ (1/2))
replacing:
E = 1,976 * 3.75 / (150 ^ (1/2))
E = 0.605
The 95% confidence interval estimate of the popilation mean is:
m - E <u <m + E
16.2 - 0.605 <u <16.2 + 0.605
15,595 <u <16,805
(15,595, 16,805)
You have to isolate x. First you start off by adding the like terms which is -3x and -x. By adding them you get -4x.
8 - 4x = 12
Then you subtract 8 on both sides since it is positive to isolate x.
-4x = 4
Then you divide -4 by both sides and get x=4/-4
4/-4 is simplified to -1 so the answer is x= -1
Answer:
Thus the length = 230 and width = 90.
Step-by-step explanation:
Farmer Fernanda wants to put a fence around her rectangular field. The length of the field is 40 feet less than 3 times the width.
She has 320 feet of fencing.
Let the length of the rectangular fence be x and the width of the fence be y.
Then the relation between them is
x = 3y - 40
Also x + y = 320
Solving these equations,
320 - y = 3y - 40
4y = 360
y = 90
x = 230
Thus the length = 230 and width = 90.
Answer:
Continuous random variables: c and e
Discrete random variables: a, b, d
Step-by-step explanation:
We have to identify whether the random variable is discrete or continuous.
- A discrete variable is a variable whose value is obtained by counting.
- A continuous random variable X takes all values in a given interval of numbers.
- Thus, a continuous variable can have values in decimals but a discrete random variable cannot take values in decimals.
a. The number of statistics students now reading a book.
Discrete random variable since number of students cannot take decimal values.
b. The number of textbook authors now sitting at a computer.
Discrete random variable since number of textbooks cannot be expressed in decimals but counted.
c. The exact time it takes to evaluate 27 plus 72.
It is a continuous random variable as it may take all values within an interval of time.
d. The number of free dash throw attempts before the first shot is made.
It is a discrete random variable since the number of throws can always be whole number.
e. The time it takes to fly from City Upper A to City Upper B.
Time is a continuous random variable.
Answer:
5
Step-by-step explanation:
f(-1)= -3(-1)³+2(-1)²
= -3(-1)+2(1)
= 3+2
=5
