A musician plans to perform 5 selections for a concert. If he can choose from 9 different selections,
how many ways can he arrange his program?

Answer:

b. The matrix is not invertible. If the given matrix is A, the columns of A do not form a linearly independent set.

Step-by-step explanation:

A square matrix is said to be invertible if the product of the matrix and its inverse result into an identity matrix.

3  0 -4

2  0  6

-3 0  8

Since the second column elements are all zero, the determinant of the matrix is zero ad this implies that the inverse of the matrix does not exist(i.e it is not invertible )

A square matrix is said to be invertible if it has an inverse.

The matrix is not invertible. If the given matrix is A, the columns of A do not form a linearly independent set.

The matrix is given as:

[tex]\left[\begin{array}{ccc}3&0&-4\\2&0&6\\-3&0&8\end{array}\right][/tex]

Calculate the determinant

The determinant of the matrix calculate as:

[tex]|A| = 3 \times(0 \times 8- 6 \times 0) - 0(2 \times 8 - 6 \times -3) -4(2 \times 0 - 0 \times -3)[/tex]

[tex]|A| = 3 \times(0) - 0(34) -4(0)[/tex]

[tex]|A| = 0 - 0 -0[/tex]

[tex]|A| = 0[/tex]

When a matrix has its determinant to be 0, then

Hence, the correct option is (b)

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Answer:

Therefore the x - coordinate of the minimum is x = -8

Step-by-step explanation:

[tex]y = 2x^2 + 32x + 56 = 2(x^2 + 16x ) + 56 = 2(x^2 + 16x +64 - 64) + 56 \\= 2(x^2 + 16x +64) - 128 + 56 = 2(x+8)^2 - 72[/tex]

Therefore the x - coordinate of the minimum is x = -8

Answer:

93 ft

Step-by-step explanation:

the area of a triangle is :

A = (b*h)/2 where b is the base and h the height(here t)

4092 = (88*t)/2

2*4092 = 88*t

t= (4092*2)/88 = 93 ft

Answer:

A 1,296

B 1,369

36 answer

Answer:

21794.495 units/month

Step-by-step explanation:

Some data are missing which i can assume as per requirement of the Question.

Let us consider that profit generated by a product is given by

p(x) =4√x

Also, consider that the profit keeps changing at a rate of $1000 per month.

Now, Using the chain rule we can write

dp/dx=(dp/dt)÷(dx/dt).

So, we  can calculate

dp/dx=2x^(-1/2)=2/√x.

As per  question we have to find out  dx/dt

Since, dx/dt= (dp/dt)/(dp/dx),

so plugging  x=1900  we get 1000√1900/2=21794.495 units/month increase in sales.

Answer:

[tex]n = \frac{k}{ {d}^{2} } [/tex]

[tex] {d}^{2} = \frac{k}{n} [/tex]

[tex]d = \sqrt{ \frac{k}{n} } [/tex]

Answer:

d = √(k/n)

Step-by-step explanation:

n = k/d²

n/1 = k/d²

Cross multiply.

k = nd²

Divide both sides by n.

k/n = nd²/n

k/n = d²

Take the square root on both sides.

√(k/n) = √(d²)

√(k/n) = d

Answer:

The answer is A because 45x2= 90 miles and 80×1 = 80 miles and 90-80= 10 so Vehicle A travels 10 miled farther than Vehicle B. Hope that helps!

Vehicle which travels the farthest is vehicle A and the distance it travels farther is 10 miles.

Speed is the unit rate in terms of distance travelled by an object and the time taken to travel the distance.

Speed is a scalar quantity as it only has magnitude and no direction.

Given that,

Speed of vehicle A = 45 miles per hour

Speed of vehicle B = 80 miles per hour

Vehicle A travels for 2 hours.

Total distance travelled = Speed × Time = 45 × 2 = 90 miles

Vehicle B travels for 1 hour.

Distance travelled = 80 miles

Vehicle A travels farthest since the distance is greater for A.

Difference in the distance = 90 - 80 = 10 miles

Hence the vehicle A travels 10 miles farther.

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Answer:

-41

Step-by-step explanation:

(7 + 1) - (11 + 39) =

= 8 - 50

= -41

Answer:

Step-by-step explanation:

Do the work inside parentheses first.  We get:

(8) - (50)(4), or

8 - 200 = -192

Answer:

A discrete data set because there are a finite number of possible values.

Step-by-step explanation:

We are given the following data set below;

When a car is randomly selected, it is found to have 8 windows.

Firstly, as we know that the discrete data is that data that have countable or finite values, and also we can observe at a point value.

On the other hand, the continuous data is that data in which there is a range of values and we can't count or observe each and every value.

So, in our question; as we can observe that we can count all the windows and it is also a finite number which means that the given data set is a discrete data set because there are a finite number of possible values.

Answer:

p-e< p < p+e

(0.061 - 0.025) < 0.061 < (0.061 + 0.025)

0.036 < 0.061 < 0.086

Step-by-step explanation:

Given;

Confidence interval CI = (a,b) = (0.036, 0.086)

Lower bound a = 0.036

Upper bound b = 0.086

To express in the form;

p-e< p < p+e

Where;

p = mean Proportion

and

e = margin of error

The mean p =( lower bound + higher bound)/2

p = (a+b)/2

Substituting the values;

p = (0.036+0.086)/2

Mean Proportion p = 0.061

The margin of error e = (b-a)/2

Substituting the given values;

e = (0.086-0.036)/2

e = 0.025

Re-writing in the stated form, with p = 0.061 and e = 0.025

p-e< p < p+e

(0.061 - 0.025) < 0.061 < (0.061 + 0.025)

0.036 < 0.061 < 0.086

Answer:

The second question

Step-by-step explanation:

The orca starts at -25 meters. She goes up 25 meters.

up 25 = +25

-25+25=0

Answer:

Option 2

Step-by-step explanation:

The orca swims at the elevation of -25 meters. The orca swims up 25 meters higher than before.

-25 + 25 = 0

Answer:

c = 5.5

Step-by-step explanation:

We can find the slope of the line using the given points (5,5) and (-3,1) using rise over run:

-4/-8 = 1/2

Now, we can plug in the slope and a point into the equation y = mx + b to find b:

5 = 1/2(5) + b

5 = 2.5 + b

2.5 = b

Then, we can plug in 6 in the point (6,c) to find c:

y = (1/2)(6) + 2.5

y = 3 + 2.5

y = 5.5

c = 5.5

Answer:

c = 5.5

Step-by-step explanation:

Find the slope with two points

m = (y2-y1)/(x2-x1)

m = (1-5)/(-3-5)

   = -4/-8

   = 1/2

If all the points are on the same line, then they have the same slope

m = (y2-y1)/(x2-x1)

Using the first and third points

1/2 = (c-5)/(6-5)

1/2 =  (c-5)/1

1/2 = c-5

Add 5 to each side

5+1/2 = c

5.5 =c

Answer:

2. Precise but not accurate

Step-by-step explanation:

In a high precision, low accuracy case study, the measurements are all close to each other (high agreement between the measurements) but not near/or close to the center of the distribution (how close a measurement is to the correct value for that measurement)

Answer:

1) There exists a real number x such that for all real numbers y, xy ≤ y.

Step-by-step explanation:

Given the statement:

"There exists a real number x such that for all real numbers y, xy > y"

The negation of the statement is:

"There exists a real number x such that for all real numbers y, xy ≤ y"

The correct option is 1

Answer:

  see attached

Step-by-step explanation:

The limit as x gets large is the ratio of the highest-degree terms. In most cases, the limit can be found by evaluating that ratio. Where an absolute value is involved, the absolute value of the highest-degree term is used.

If the ratio gives x to a positive power, the limit does not exist. If the ratio gives x to a negative power, the limit is zero.

The arrangement of functions according to the given condition

[tex]m(x)=\frac{4x^{2}-6 }{1-4x^{2} }[/tex]

[tex]h(x)=\frac{x^{3} -x^{2} +4}{1-3x^{2} }[/tex]

[tex]k(x)=\frac{5x+1000}{x^{2} }[/tex]

[tex]i(x)=\frac{x-1}{|1-4x| }[/tex]

[tex]g(x)=\frac{|4x-1|}{x-4}[/tex]

[tex]l(x)=\frac{5x^{2} -4}{x^{2} +1}[/tex]

[tex]f(x)=\frac{x^{2} -1000}{x-5}[/tex]

[tex]j(x)=\frac{x^{2}-1 }{|7x-1|}[/tex]

A limit is the value that  a function approaches as the input approaches some value.

According to the given question

[tex]l(x)=\frac{5x^{2} -4}{x^{2} +1}[/tex]

⇒[tex]\lim_{nx\to \infty} \frac{5x^{2} -1}{x^{2} +1}[/tex]

⇒[tex]\lim_{x \to \infty} \frac{x^{2} }{x^{2} } \frac{5-\frac{1}{x^{2} } }{1+\frac{1}{x^{2} } }[/tex]

= 5           ([tex]\frac{1}{x^{2} } = 0[/tex] ,as x tends to infinity  [tex]\frac{1}{x^{2} }[/tex] tends to 0)

[tex]i(x)=\frac{x-1}{|1-4x|}[/tex]

⇒[tex]\lim_{x \to \infty} \frac{x-1}{|1-4x|}[/tex] =  [tex]\lim_{x \to \infty} \frac{x}{x} \frac{1-\frac{1}{x} }{|\frac{-1}{4}+\frac{1}{x} | }[/tex]  =[tex]\frac{1}{\frac{1}{4} }[/tex] =[tex]\frac{1}{4}[/tex]

As x tends to infinity 1/x tends to 0, and |[tex]\frac{-1}{4}[/tex]| gives 1/4

[tex]f(x)= \frac{x^{2} -1000}{x--5}[/tex]

⇒[tex]\lim_{x \to \infty} \frac{x^{2} -1000}{x-5}[/tex]= [tex]\lim_{x \to \infty} \frac{x^{2} }{x} \frac{1-\frac{1000}{x^{2} } }{1-\frac{5}{x} }[/tex]= [tex]\lim_{x \to \infty} x\frac{1-\frac{1000}{x^{2} } }{1-\frac{5}{x} }[/tex] ⇒ limit doesn't exist.

[tex]m(x)=\frac{4x^{2}-6 }{1-4x^{2} }[/tex]

⇒[tex]\lim_{x\to \infty} \frac{4x^{2} -6}{1-4x^{2} }[/tex]=[tex]\lim_{x\to \infty} \frac{x^{2} }{x^{2} } \frac{4-\frac{6}{x^{2} } }{\frac{1}{x^{2} } -4}[/tex]  [tex]= \lim_{n \to \infty} \frac{4}{-4}[/tex] = -1

As x tends to infinity [tex]\frac{1}{x^{2} }[/tex] tends to 0.

[tex]g(x)=\frac{|4x-1|}{x-4}[/tex]

⇒[tex]\lim_{x\to \infty} \frac{|4x-1|}{x-4}[/tex] = [tex]\lim_{x \to \infty} \frac{|x|}{x} \frac{4-\frac{1}{x} }{1 -\frac{4}{x} } }[/tex] = 4

as x tends to infinity 1/x tends to 0

and |x|=x ⇒[tex]\frac{|x|}{x}=1[/tex]

[tex]h(x)=\frac{x^{3}-x^{2} +4 }{1-3x^{3} }[/tex][tex]\lim_{x \to \infty} \frac{x^{3} -x^{2} +4}{1-3x^{3} }[/tex][tex]= \lim_{x \to \infty} \frac{x^{3} }{x^{3} } \frac{1-\frac{1}{x}+\frac{4}{x^{3} } }{\frac{1}{x^{3} -3} }[/tex]  = [tex]\frac{1}{-3}[/tex] =[tex]-\frac{1}{3}[/tex]

[tex]k(x)=\frac{5x+1000}{x^{2} }[/tex]

[tex]\lim_{x \to \infty} \frac{5x+1000}{x^{2} }[/tex] = [tex]\lim_{x \to \infty} \frac{x}{x} \frac{5+\frac{1000}{x} }{x}[/tex] =0

As x tends to infinity 1/x tends to 0

[tex]j(x)= \frac{x^{2}-1 }{|7x-1|}[/tex]

[tex]\lim_{x \to \infty} \frac{x^{2}-1 }{|7x-1|}[/tex] = [tex]\lim_{x \to \infty} \frac{x}{|x|}\frac{x-\frac{1}{x} }{|7-\frac{1}{x}| }[/tex]  = [tex]\lim_{x \to \infty} 7x[/tex] = limit doesn't exist.

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Answer:

104.93 in

Step-by-step explanation:

When we draw out a picture of our triangle, we should see that we need to use sin∅ to solve:

sin23° = 41/x

xsin23° = 41

x = 41/sin23°

x = 104.931

Answer:  24

Step-by-step explanation:

Let's find one solution:

3x² + 7x + c = 0

a=3 b=7  c=c

First, let's find c so that it has REAL ROOTS.

⇒ Discriminant (b² - 4ac) ≥ 0

                         7² - 4(3)c ≥ 0

                         49 - 12c ≥ 0

                               -12c  ≥ -49

                                [tex]c\leq\dfrac{-49}{-12}\quad \rightarrow c\leq \dfrac{49}{12}[/tex]      

Since c must be a positive integer, 1 ≤ c ≤ 4

Example: c = 4

3x² + 7x + 4 = 0

(3x + 4)(x + 1) = 0

x = -4/3, x = -1         Real Roots!

You need to use Quadratic Formula to solve for c = {1, 2, 3}

Valid solutions for c are: {1, 2, 3, 4)

Their product is: 1 x 2 x 3 x 4 = 24

Answer:

$3x^2+7x+c=0$

comparing above equation with ax²+bx+c

a=3

b=7

c=1

using quadratic equation formula

[tex]x = \frac{ - b + - \sqrt{b {}^{2} - 4ac} }{ 2a} [/tex]

x=(-7+-√(7²-4×3×1))/(2×3)

x=(-7+-√13)/6

taking positive

x=(-7+√13)/6=

taking negative

x=(-7-√13)/6=

Answer:

13 Compute using the 2 right angles, we know that m<FIG=90* and

Part A

g(x) = 3x+1

g(-4) = 3(-4)+1 ... every x replaced with -4

g(-4) = -12+1

g(-4) = -11

Plug this into the f(x) function

f(x) = x^2 - 2x

f( g(-4) ) = (g(-4))^2 - 2( g(-4) )

f( g(-4) ) = (-11)^2 - 2(-11)

f( g(-4) ) = 121 + 22

====================================================

Part B

Plug the g(x) function into the f(x) function

f(x) = x^2 - 2x

f( g(x) ) = ( g(x) )^2 - 2( g(x) ) ... replace every x with g(x)

f( g(x) ) = (3x+1)^2 - 2(3x+1)

f( g(x) ) = (9x^2+6x+1) + (-6x-2)

f( g(x) ) = 9x^2+6x+1-6x-2

Note that we can plug x = -4 into this result and we would get

f( g(x) ) = 9x^2-1

f( g(-4) ) = 9(-4)^2-1

f( g(-4) ) = 9(16)-1

f( g(-4) ) = 144-1

f( g(-4) ) = 143 which was the result from part A

====================================================

Part C

Replace g(x) with y. Then swap x and y. Afterward, solve for y to get the inverse.

[tex]g(x) = 3x+1\\\\y = 3x+1\\\\x = 3y+1\\\\3y+1 = x\\\\3y = x-1\\\\y = \frac{1}{3}(x-1)\\\\y = \frac{1}{3}x-\frac{1}{3}\\\\g^{-1}(x) = \frac{1}{3}x-\frac{1}{3}\\\\[/tex]

Answer: the answer is d sin30degrees equal 5/x because sin is opposite over hyponuese

Step-by-step explanation:

Given that Rita is making a beaded bracelet. She has a collection of 160 blue beads, 80 gray beads, and 240 pink beads. We are to calculate the probability that Rita will need to pick atleast 5 beads before she picks a grey bead from her collection.

Prob for drawing atleast 5 beads before she picks a grey bead from her collection

= 1-Prob for drawing atleast one grey beed in the first 5 draws.

(Because these two are complementary events)

no of grey beeds drawn in first 5 trials is

Bi=(5,1/6)

Prob for drawing atleast one grey beed in the first 5 draws.

=1-Prob of no grey

Hence required prob=P(X=0 in first 5 draws)

= 0.4018

6th beeds onwards can be grey also.

Nearest answer is c)0.45

Answer:

o.45

Step-by-step explanation:

i just did the test

Answer:

after 9 weeks it would become 9*1+10=19 inches

and after w weeks it will be w*1+10 inches tall

hope this helps

Step-by-step explanation:

Answer:

a) 19 inches

b) 10+w inches

Step-by-step explanation:

The equation for this problem is 10 + w.  In the first part, w = 9, so the plant is 19 inches tall.

Answer:

The length of the third side of fence is 11.4 m

Step-by-step explanation:

Solution:-

- We are to mow a triangular piece of land. We are given the description of motion and the orientation of land-mower while fencing.

- From one corner of the triangular land, the land-mower travels H1 = 5.7 m at θ1 = 0.3 radians north of east. We will use trigonometric ratios to determine the amount traveled ( B1 ) in the east direction.

                                  [tex]cos ( theta_1 ) = \frac{B_1}{H_1}[/tex]

Where,

                          B1: Is the base length of the right angle triangle

                          H1: Hypotenuse of the right angle triangle

Therefore,

                                [tex]B_1 = H_1*cos ( theta_1 )\\\\B_1 = 5.7*cos ( 0.3 )\\\\B_1 = 5.44541 m[/tex]

- Similarly, from the other corner of the triangular land. The land-mower moves a lateral distance of H2 = 9m and directed θ2 = 0.9 radians north of west. We will use trigonometric ratios to determine the amount traveled ( B2 ) in the west direction.

                                [tex]cos ( theta_2 ) = \frac{B_2}{H_2} \\[/tex]

Where,

                          B2: Is the base length of the right angle triangle

                          H2: Hypotenuse of the right angle triangle

Therefore,

                                 [tex]B_2 = H_2*cos ( theta_2 )\\\\B_2 = 9*cos(0.9)\\\\B_2 = 5.59448 m[/tex]

- The total length of the third side of the fence would be the sum of bases of the two right angles formed by the land-mower motion at each corner.

                                [tex]L = B_1 + B_2\\\\L = 5.44541 + 5.59448\\\\L = 11.4 m[/tex]

Answer:

452.4

Step-by-step equation:

surface area of a sphere formula= 4πr²

plug 6 in for r

4π(6)² =452.389 rounded  to 452.4

Answer:

16

Step-by-step explanation:

X^2 + 8x= 11

Take the coefficient of x

8

Divide by 2

8/2 =4

Square it

4^2 = 16

Add 16 to each side

Answer:

18/90=9/x and to find x use proportion so first 90*9=18x and 810=18x and x-45

Step-by-step explanation:

Answer:

45 stores are at University Mall

Step-by-step explanation:

The ratio of malls that sell shoes at North Area mall are 18 out of 90, which simplifies to one fifth of stores. Since the same ratio holds for the University Mall, and 9 is half of 18, the amount of stores at University Mall is 45 because 45 is half of 90.

Answer:

Point A

Step-by-step explanation:

We know that on a coordinate plane, negative numbers can be found by moving down or moving to the left. This point must be found by moving down and left. To establish whether it is point A or point Y, we can remember that x coordinates move left and right and y coordinates move up and down. So, we would need to move 3.5 units left for x and then 4.5 units down for y. This leads us to point A.

hope this helps!

Answer:

it is point A

Step-by-step explanation:

Answer:

Hey!

Your answer is YES!

AKA the Last Option on your screen!

Step-by-step explanation:

It is this because...

They both have the angles 105 in it...

And looking at the other angle on the smaller one (25)

50 + 25 = 75 ... 180 - 75 = 105

WE HAVE 105 as an angle on the larger triangle...which makes them SIMILAR but congruent Angles!

It cant be the "corresponding sides" as we do not have the notations (lines intersecting the sides) that let us know that the lines are the same.

Hope this helps!

Answer:

(a)[tex]A(t)=18e^{ -\frac{t}{100}}[/tex]

(b)13.3 kg

Step-by-step explanation:

The volume of brine in the tank = 4000L

Initial Amount of salt, A(0)=18 kg

The rate of change in the amount of salt in the tank at any time t is represented by the equation:

[tex]\dfrac{dA}{dt}=$Rate In$-$Rate Out[/tex]

Rate In = (concentration of salt in inflow)(input rate of brine)

Since pure water enters the tank, concentration of salt in inflow =0

Rate In = 0

Rate Out=(concentration of salt in outflow)(output rate of brine)

[tex]=\frac{A(t)}{4000}\times 40\\ =\frac{A(t)}{100}[/tex]

Therefore:

[tex]\dfrac{dA}{dt}=-\dfrac{A(t)}{100}\\\dfrac{dA}{dt}+\dfrac{A(t)}{100}=0[/tex]

This is a linear D.E. which we can then solve for A(t).

Integrating Factor: [tex]e^{\int \frac{1}{100}d}t =e^{ \frac{t}{100}[/tex]

Multiplying all through by the I.F.

[tex]\dfrac{dA}{dt}e^{ \frac{t}{100}}+\dfrac{A(t)}{100}e^{ \frac{t}{100}}=0e^{ \frac{t}{100}}\\(Ae^{ \frac{t}{100}})'=0[/tex]

Taking integral of both sides

[tex]Ae^{ \frac{t}{100}}=C\\A(t)=Ce^{ -\frac{t}{100}}[/tex]

Recall our initial condition

A(0)=18 kg

[tex]18=Ce^{ -\frac{0}{100}}\\C=18[/tex]

Therefore, the amount of salt in the tank after t minutes is:

[tex]A(t)=18e^{ -\frac{t}{100}}[/tex]

(b)When t=30 mins

[tex]A(30)=18e^{ -\frac{30}{100}}\\=18e^{ -0.3}\\=13.3 $kg(correct to 1 decimal place)[/tex]

The amount of salt in the tank after 30 minutes is 13.3kg

In this exercise we have to use the integral to calculate the salt concentration:

(a)[tex]A(t)=18e^{-\frac{t}{100} }[/tex]

(b)[tex]13.3 kg[/tex]

Knowing that the volume of brine in the tank = 4000L, the initial Amount of salt, A(0)=18 kg. The rate of change in the amount of salt in the tank at any time t is represented by the equation:

[tex]\frac{dA}{dt} = Rate \ in - Rate \ out[/tex]

Rate In = (concentration of salt in inflow)(input rate of brine). Since pure water enters the tank, concentration of salt in inflow =0.

Rate In = 0

Rate Out=(concentration of salt in outflow)(output rate of brine)

[tex]\frac{A(t)}{4000}*(40)[/tex]

[tex]= \frac{A(t)}{100}[/tex]

Therefore:

[tex]\frac{dA}{dt} = \frac{A(t)}{100}\\\frac{dA}{dt} + \frac{A(t)}{100} = 0[/tex]

This is a linear D.E. which we can then solve for A(t). Integrating Factor:  [tex]e^{\int\limits {\frac{t}{100} } \, dt\\e^{t/100}[/tex] . Multiplying all through by the Integrating Factor:  

[tex]\frac{dA}{dt} = e^{t/100}+\frac{A(t)}{100}e^{t/100}\\(Ae^{1/100})'=0[/tex]

Taking integral of both sides:

[tex]Ae^{t/100}=C\\A(t)=Ce^{-t/100}[/tex]

Recall our initial condition:

[tex]A(0)=18 kg\\18=Ce^{0}\\C=18[/tex]

Therefore, the amount of salt in the tank after t minutes is:

[tex]A(t)=18e^{-t/100}[/tex]

(b)When t=30 mins

[tex]A(30)=18e^{-30/100}\\=18e^{-0.3}\\=13.3[/tex]

The amount of salt in the tank after 30 minutes is 13.3kg.

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Answer:

yes it is little different  from the confidence interval (30.4 ≤μ≤ 32.8) changes statistics

90% confidence interval estimate of the mean is

(30.1048 , 33.0952)

Step-by-step explanation:

Step(I):-

Given sample size 'n' = 153

Given mean of the sample x⁻ = 31.5

Sample standard deviation 'S' = 7.1 h g

90% confidence interval estimate of the mean is determined by

[tex](x^{-} - t_{\frac{\alpha }{2} } \frac{S}{\sqrt{n} } , x^{-} + t_{\frac{\alpha }{2} } \frac{S}{\sqrt{n} } )[/tex]

Degrees of freedom

ν = n-1 = 153-1 =152

t₀.₀₅ =1.9757

Step(ii)

90% confidence interval estimate of the mean is

[tex](x^{-} - t_{\frac{\alpha }{2} } \frac{S}{\sqrt{n} } , x^{-} + t_{\frac{\alpha }{2} } \frac{S}{\sqrt{n} } )[/tex]

[tex](31.5 - 1.9757 } \frac{7.1}{\sqrt{153} } , 31.5 + 1.9757 \frac{7.1}{\sqrt{153} } )[/tex]

( 31.5 - 1.1340 , 31.5 + 1.1340)

(30.366 , 32.634)

90% confidence interval estimate of the mean is

(30.4 , 32.6)

b)

Given sample size 'n' = 15

Given mean of the sample x⁻ = 31.6

Sample standard deviation 'S' = 2.7 h g

90% confidence interval estimate of the mean is determined by

[tex](x^{-} - t_{\frac{\alpha }{2} } \frac{S}{\sqrt{n} } , x^{-} + t_{\frac{\alpha }{2} } \frac{S}{\sqrt{n} } )[/tex]

Degrees of freedom

ν = n-1 = 15-1 =14

t₀.₀₅ =2.1448

90% confidence interval estimate of the mean is

[tex](x^{-} - t_{\frac{\alpha }{2} } \frac{S}{\sqrt{n} } , x^{-} + t_{\frac{\alpha }{2} } \frac{S}{\sqrt{n} } )[/tex]

[tex](31.6 - 2.1448 } \frac{2.7}{\sqrt{15} } , 31.6 + 2.1448 \frac{2.7}{\sqrt{15} } )[/tex]

( 31.6 - 1.4952 , 31.6 + 1.4952)

(30.1048 , 33.0952)

Conclusion:-

yes it is little different  from the confidence interval (30.4 ≤μ≤32.8)