Answer: He should add 8 gallons of water to make 5% bleach solution.
Step-by-step explanation:
Let the number of gallons of water he should add be 'x'.
Since we have given that
Total number of gallon we have = 8
It has 10% beach solution i.e.
We need to make it a 5% bleach solution by adding water to it.
so, our equation becomes,
Hence, he should add 8 gallons of water to make 5% bleach solution.
Answer:
(3)11
Step-by-step explanation:
We are given that
We have to find the sum of positive roots of the equation.
Factor of 336
2,3,4,6,8,7,
Let x=2
x=2 is not the root of equation
x=-2
Hence x=-2 is the root of equation.
x+2 is a factor of equation.
x=3
Therefore, x=3 is the root of equation.
Positive roots are 3 and 8
Sum of positive roots=3+8=11
Option (3) is true.
Answer:
For x∈ {-∞,-3} y<0, below x-axis
x∈ {-3,-1} y>0, above x-axis
x∈ {-1,4} y<0, below x-axis
x∈ {4,∞} y>0, above x-axis
Step-by-step explanation:
f(x)=
=0
For x∈ {-∞,-3} y<0, below x-axis
x∈ {-3,-1} y>0, above x-axis
x∈ {-1,4} y<0, below x-axis
x∈ {4,∞} y>0, above x-axis
Answer:
A 90% confidence interval of the true mean is [$119.86, $123.34].
Step-by-step explanation:
We are given that an irate student complained that the cost of textbooks was too high. He randomly surveyed 36 other students and found that the mean amount of money spent on textbooks was $121.60.
Also, the standard deviation of the population was $6.36.
Firstly, the pivotal quantity for finding the confidence interval for the population mean is given by;
P.Q. = ~ N(0,1)
where, = sample mean amount of money spent on textbooks = $121.60
= population standard deviation = $6.36
n = sample of students = 36
= population mean
<em>Here for constructing a 90% confidence interval we have used One-sample z-test statistics as we know about population standard deviation.</em>
<em />
So, 95% confidence interval for the population mean, is ;
P(-1.645 < N(0,1) < 1.645) = 0.90 {As the critical value of z at 5% level
of significance are -1.645 & 1.645}
P(-1.645 < < 1.645) = 0.90
P( <
<
) = 0.90
P( <
<
) = 0.90
<u>90% confidence interval for</u> = [
,
]
= [ ,
]
= [$119.86, $123.34]
Therefore, a 90% confidence interval of the true mean is [$119.86, $123.34].