Statistics professors believe the average number of headaches per semester for all students is more than 18. From a random sample of 15 students, the professors find the mean number of headaches is 19 and the standard deviation is 1.7. Assume the population distribution of number of headaches is normal.

Answer:

Low             Q1                Median              Q3                 High

6                  9                     11                      12.5                14

The interquartile range = 3.5

Step-by-step explanation:

Given that:

Consider the following ordered data. 6 9 9 10 11 11 12 13 14

From the above dataset, the highest value = 14  and the lowest value = 6

The median is the middle number = 11

For Q1, i.e the median  of the lower half

we have the ordered data = 6, 9, 9, 10

here , we have to values as the middle number , n order to determine the median, the mean will be the mean average of the two middle numbers.

i.e

median = [tex]\dfrac{9+9}{2}[/tex]

median = [tex]\dfrac{18}{2}[/tex]

median = 9

Q3, i.e median of the upper half

we have the ordered data = 11 12 13 14

The same use case is applicable here.

Median = [tex]\dfrac{12+13}{2}[/tex]

Median = [tex]\dfrac{25}{2}[/tex]

Median = 12.5

Low             Q1                Median              Q3                 High

6                  9                     11                      12.5                14

The interquartile range = Q3 - Q1

The interquartile range =  12.5 - 9

The interquartile range = 3.5

Answer:

x

Step-by-step explanation:

probability is the branch of mathematics concerning numeral descriptions of how likely an event is to occur or how likely it is that a proposition is true

The value of function at x= -1 is f(-1) = 4.

We have the function as

f(x) = 2x² - 3x -1

To find the value of f(-1) when f(x) = 2x² - 3x -1, we substitute x = -1 into the expression:

f(-1) = 2(-1)² - 3(-1) - 1

      = 2(1) + 3 - 1

      = 2 + 3 - 1

      = 4.

Therefore, the value of function at x= -1 is f(-1) = 4.

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Answer: [tex]-44\dfrac{4}{9}[/tex]

Step-by-step explanation:

The given expression: [tex]-36\dfrac{4}{9}-(-10\dfrac{2}{9})-(18\dfrac{2}{9})[/tex]

Here, [tex]36\dfrac{4}{9}=\dfrac{36\times9+4}{9}=\dfrac{328}{9}[/tex]

[tex](10\dfrac{2}{9})=\dfrac{92}{9}\\\\(18\dfrac{2}{9})=\dfrac{9\times18+2}{9}=\dfrac{164}{9}[/tex]

That is

[tex]-36(\dfrac{4}{9})-(-10\dfrac{2}{9})-(18\dfrac{2}{9}) = -\dfrac{328}{9}-(-\dfrac{92}{9})-\dfrac{164}{9}\\\\=-\dfrac{328}{9}+\dfrac{92}{9}-\dfrac{164}{9}\\\\=\dfrac{-328+92-164}{9}\\\\=\dfrac{-400}{9}\\\\=-44\dfrac{4}{9}[/tex]

Answer:

12). LM = 37.1 units

13). c = 4.6 mi

Step-by-step explanation:

12). LM² = 23² + 20² - 2(23)(20)cos(119)°

    LM² = 529 + 400 - 920cos(119)°

    LM² = 929 - 920cos(119)°

    LM = [tex]\sqrt{929+446.03}[/tex]

          = [tex]\sqrt{1375.03}[/tex]

          = 37.08

          ≈ 37.1 units

13). c² = 5.4² + 3.6² - 2(5.4)(3.6)cos(58)°

    c² = 29.16 + 12.96 - 38.88cos(58)°

    c² = 42.12 - 38.88cos(58)°

    c = [tex]\sqrt{42.12-20.603}[/tex]

    c = [tex]\sqrt{21.517}[/tex]

    c = 4.6386

    c ≈ 4.6 mi

Answer:

150,000

Step-by-step explanation:

1 m = 100 cm

260 m = 260 * 100 cm = 26000 cm

15 m = 15 * 100 cm = 1500 cm

area of floor = LW = 26000 cm * 1500 cm = 39,000,000 cm^2

area of 1 tile = 26 cm + 10 cm = 260 cm^2

number of tiles needed = 39,000,000/260 = 150,000

Answer: 150,000 tiles

Answer:

Step-by-step explanation:

from the question,

the mean 14

the standard deviation is 3

and sample size is 10.

since the n which is the sample size is 10, then the distribution is mound shaped.

why?

this is due to the fact that the random variable from which we took the sample is mound shaped.

The sampling distribution of the mean is normally distributed although the question says the random variable is not normally distributed. so the shape is bell shaped and normally distributed.

the standard deviation of the mean is

3/√10

= 0.948

Answer: 7 mi

Step-by-step explanation: since the distance from bluepoint to Manchester is 12 9/10 mi and you know that bluepoint to Silverstone is 5 9/10 subtract that and you get 7 mi as your answer

Answer:

7 miles

Step-by-step explanation:

Hey there!

Well given BM and BS, we need to subtract them.

12 9 /10 - 5 9/10

9/10 - 9/10 = 0

12 - 5 = 7

Silvergrove to Manchester is 7 miles.

Hope this helps :)

Answer:

  28) -1

  29) 9

  30) x^2+4x+7

  31) x-2

Step-by-step explanation:

Given:

  f(x) = x + 2

  g(x) = x^2 +3

Find:

  28) f(-3)

  29) f(g(2))

  30) g(f(x))

  31) f-1(x)

Solution:

Put the function argument values into the expression and do the arithmetic.

28) f(-3) = (-3) +2 = -1

__

29) f(g(2)) = f((2)^2 +3) = f(7) = (7) +2 = 9

__

30) g(f(x)) = g(x+2) = (x+2)^2 +3 = x^2 +4x +7

__

31) The meaning of y = f^-1(x) is x = f(y).

  x = f(y) = y+2

  y = x -2

  f^-1(x) = x -2

Answer:

[tex]\huge\boxed{a=9 ; b = -8}[/tex]

Step-by-step explanation:

[tex]f(x) = \frac{ax+b}{x}[/tex]

Putting x = 1

=> [tex]f(1) = \frac{a(1)+b}{1}[/tex]

Given that f(1) = 1

=> [tex]1 = a + b[/tex]

=> [tex]a+b = 1[/tex]  -------------------(1)

Now,

Putting x = 2

=> [tex]f(2) = \frac{a(2)+b}{2}[/tex]

Given that f(2) = 5

=> [tex]5 = \frac{2a+b}{2}[/tex]

=> [tex]2a+b = 5*2[/tex]

=> [tex]2a+b = 10[/tex]  ----------------(2)

Subtracting (2) from (1)

[tex]a+b-(2a+b) = 1-10\\a+b-2a-b = -9\\a-2a = -9\\-a = -9\\a = 9[/tex]

For b , Put a = 9 in equation (1)

[tex]9+b = 1\\Subtracting \ both \ sides \ by \ 9\\b = 1-9\\b = -8[/tex]

Answer:

D

Step-by-step explanation:

To determine the range we must solve this inequality;

● 1200000<1800000-250x<1300000

Substract 1800000 from both sides.

● 1200000-1800000<1800000-250x<1300000-1800000

● -600000< -250x < -500000

Divide both sides by 250

● -600000/250 < -250x/250 < -500000/250

● -2400 < -x < -2000

Multiply both sides by -1 and switch the signs

● 2000 < x < 2400

The correct option is D. 2000<= x <= 2400

Given, the value of an airplane depends on the flight hours,

[tex]V= 1800000-250x[/tex], here x is the flight hours.

We have to calculate the range of x After one year.

Since, [tex]V= 1800000-250x[/tex]

[tex]250x=1800000-V\\\\x=\dfrac{1800000-V}{250}[/tex]

Since the value of the plane is between $1,200,000 and $1,300,000. So,

[tex]x=\dfrac{1800000-1200000}{250}[/tex]

[tex]x=\dfrac{600000}{250}[/tex]

[tex]x=2400\\[/tex]

When V is 1300000 then x will be,

[tex]x=\dfrac{1800000-1300000}{250} \\[/tex]

[tex]x=\dfrac{500000}{250}[/tex]

[tex]x=2000[/tex]

Hence the range of x will be from 2000 to 2400.

The correct option is D. 2000<= x <= 2400.

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Answer:

Step-by-step explanation: distribute -3 to the parenthesis (-2y-4) to eliminate the parenthesis. you’ll be left with 6y +12 -5y-2. From there you combine like terms. do 6y-5y= 1y or just y and 12-2 = 10. your answer would be 10

Answer:

Step-by-step explanation:

Decay of carbon - 14 is exponential in nature . It decays as follows .

[tex]N=N_0e^{-\lambda t}[/tex]  λ is called decay constant .

λ = .693 / T where T is half life .

Half life of carbon-14 is 5700 years

λ = .693 / T

= .693 / 5700

= 12.158 x 10⁻⁵ year⁻¹

[tex]N=N_0e^{-\lambda t}[/tex]

N = .71 N₀

[tex].71 N_0 =N_0e^{-\lambda t}[/tex]

[tex].71 =e^{-\lambda t}[/tex]

Taking ln on both sides

ln .71 = - λ t

ln .71 = - 12.158 x 10⁻⁵  t

-0.3425 =  - 12.158 x 10⁻⁵  t

t = .3425 / 12.158 x 10⁻⁵

2817  years .

Step-by-step explanation:

Hello, there!!!

It's so simple here,

Here,

we have is 1 angle is 120°and other is 3x°.

now,

3x°=120° {because when two st.line intersects eachother then the opposite angle formed are equal}

so, 3x°=120

or, x=120°/3

=40°

Therefore, the value of x is 40°.

Hope it helps....

Answer:

The  90% confidence interval is  [tex]\$ \ 30313.9< \mu < \$ \ 33686.13[/tex]

Step-by-step explanation:

From the question we are told that

   The  sample size is  n =  64

     The sample  mean is  [tex]\= x = \$ 32, 000[/tex]

     The  standard deviation is  [tex]\sigma= \$ 8, 200[/tex]

Given that the confidence interval is  90% then the level of significance is mathematically evaluated as

             [tex]\alpha = 100 - 90[/tex]

             [tex]\alpha = 10 \%[/tex]

            [tex]\alpha = 0.10[/tex]

Next we obtain the critical value of  [tex]\frac{ \alpha }{2}[/tex] from the normal distribution table , the value is  

       [tex]Z_{\frac{\alpha }{2} } = 1.645[/tex]

  Generally the margin of error is mathematically represented as

        [tex]E = Z_{\frac{\alpha }{2} } * \frac{ \sigma }{ \sqrt{n} }[/tex]

  =>   [tex]E = 1.645 * \frac{ 8200 }{ \sqrt{64} }[/tex]

  =>   [tex]E = 1686.13[/tex]

The 90% confidence interval is mathematically represented as

      [tex]\= x - E < \mu < \= x + E[/tex]

 =>    [tex]32000 - 1689.13 < \mu < 32000 + 1689.13[/tex]

=>    [tex]\$ \ 30313.9< \mu < \$ \ 33686.13[/tex]

Answer:

[tex]\large\boxed{\frac{3}{2}a^{8}}[/tex]

Step-by-step explanation:

([tex]a^{8}[/tex]) * [tex]\frac{3}{2}[/tex]

Remove the parenthesis by multiplying

[tex]\frac{3}{2}[/tex][tex]a^{8}[/tex]

This expression cannot be simplified further

[tex]\large\boxed{\frac{3}{2}a^{8}}[/tex]

Hope this helps :)

Answer:

5x^3-2

[tex]ax^{3} +bx^{2} +cx+d\\5x^{3}-given\\ d=-2-given\\5x^{3} -2[/tex]

Explanation:

The two terms are [tex]5x^3[/tex] and [tex]2[/tex]. Terms are separated by either a plus or minus.

We can write it as [tex]5x^3+(-2)[/tex] which is an equivalent form. Here the two terms are [tex]5x^3[/tex] and [tex]-2[/tex]. This is because adding a negative is the same as subtracting.

The coefficient is the number to the left of the variable.

The degree is the largest exponent, which helps form the leading term.

The third degree polynomial written above is considered a cubic binomial. "Cubic"  refers to the third degree, while "binomial" means there are 2 terms.

We can write something like [tex]5x^3[/tex] as 5x^3 when it comes to computer settings.

Answer:

69

Step-by-step explanation:

90-21=69

Answer:

69 degrees

Step-by-step explanation:

The full angle = 90 degrees.

One part of the full angle = 21 degrees

The other part of the full angle = x

Other angle = 90 - 21

=> the other angle = 69 degrees

Answer:

We conclude that the rate of smoking among those with four years of college is less than the 27% rate for the general population.

Step-by-step explanation:

We are given that a survey showed that among 785 randomly selected subjects who completed four years of college, 144 of them are smokers.

Let p = population proportion of smokers among those with four years of college

So, Null Hypothesis, [tex]H_0[/tex] : p [tex]\geq[/tex] 27%      {means that the rate of smoking among those with four years of college is more than or equal to the 27% rate for the general population}

Alternate Hypothesis, [tex]H_A[/tex] : p < 27%      {means that the rate of smoking among those with four years of college is less than the 27% rate for the general population}

The test statistics that will be used here is One-sample z-test for proportions;

                             T.S.  =  [tex]\frac{\hat p-p}{\sqrt{\frac{p(1-p)}{n} } }[/tex]  ~   N(0,1)

where, [tex]\hat p[/tex] = sample proportion of smokers = [tex]\frac{144}{785}[/tex] = 0.18

           n = sample of subjects = 785

So, the test statistics =  [tex]\frac{0.18-0.27}{\sqrt{\frac{0.27(1-0.27)}{785} } }[/tex]

                                     =  -5.68

The value of z-test statistics is -5.68.

             P-value = P(Z < -5.68) = Less than 0.0001

Now, at a 0.01 level of significance, the z table gives a critical value of -2.3262 for the left-tailed test.

Since the value of our test statistics is less than the critical value of z, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region.

Therefore, we conclude that the rate of smoking among those with four years of college is less than the 27% rate for the general population.

Answer:

50%

Step-by-step explanation:

Girls                                            Boys

total:                 59                     total:                              41

- Chemistry       35                   - Physics                           2

                       = 24                                    =                     39

                                                 - Chemistry ( 30 - 6 )      24

                                                                   =                     15

Total boys and girls for Biology = 35 + 15 = 50

% = 50/100*100

   = 50%

Answer:

x > -6

Step-by-step explanation:

-5x — 10 < 20

Add 10 to each side

-5x — 10+10 < 20+10

-5x < 30

Divide each side by -5, remembering to flip the inequality

-5x/-5 > 30/-5

x > -6

Answer:

Step-by-step explanation:

[tex]-5x - 10 < 20\\\\\mathrm{Add\:}10\mathrm{\:to\:both\:sides}\\\\-5x-10+10<20+10\\\\\mathrm{Multiply\:both\:sides\:by\:-1\:\left(reverse\:the\:inequality\right)}\\\\\left(-5x\right)\left(-1\right)>30\left(-1\right)\\\\\mathrm{Simplify}\\\\5x>-30\\\\\mathrm{Divide\:both\:sides\:by\:}5\\\\\frac{5x}{5}>\frac{-30}{5}\\\\x>-6[/tex]

Answer:18 ft

Step-by-step explanation: Perimeter=2(L+B)

Perimeter=2(7 + 2)

2×9=18

Answer:

18feet.

Step-by-step explanation:

To find the perimemter of a rectangle, you just add all the sides.

A rectangle has 4 sides in total, where 2 are equal, and the other 2 are als equal.

So, you just add 7+2+7+2, which gives 18.

This is why, the perimeter of this rectangle is 18feet.

Hope this helped, have a nice day!

Answer:

so to get a third you divide it by 3

first convert it to fraction

so it is 26/3

so do 26/3 divided by 3

so we do keep switch flip

26/3*1/3

so answer is 26/9 or 2 8/9

Step-by-step explanation:

Answer:

[tex]\large \boxed{\mathrm{2 \ 8/9 \ tablespoons \ of \ red \ chilies }}[/tex]

Step-by-step explanation:

8 2/3 tablespoons of red chilies is required for a recipe.

One-third of the original recipe would mean that the quantity of red chilies will be also one-third.

8 2/3 × 1/3

Convert to an improper fraction.

26/3 × 1/3

Multiply the fractions.

26/(3 × 3) = 26/9

Convert to a mixed fraction.

26/9 = 2 8/9

Answer:

36

Step-by-step explanation:

formula of area for square:

A=s^2

s=6

A=6^2

A=36

Answer:

36

Step-by-step explanation:

I got it right

Answer:

y=4/7x

Step-by-step explanation:

perpendicular lines have opposite slopes. that means reciprocal and opposite sign.

Answer:

Within the factors hindering expression in music, tempo is the most important number of factors such as your mood.

Step-by-step explanation:

If one wants to convey a message, they should try these:

a) Use real life

b) introduce symbolism

c) convey sensory disruption, e.t.c.

Hope these helps.

Hey there! I'm happy to help!

Lines that are parallel have the same slopes because they are increasing or decreasing at the same rate and therefore will never bump into each other.

We see that y=2 has a slope of 0 because there is no x that we can see in the equation. This is just a flat line.

If the line we are looking for is flat; it stays at the same y-value the entire time. We see that  the y-value for this line of ours is -6. Therefore, the answer is C. y=-6.

I hope that this helps! Have a wonderful day!

Answer:

Lines that are parallel have the same slopes because they are increasing or decreasing at the same rate and therefore will never bump into each other.

We see that y=2 has a slope of 0 because there is no x that we can see in the equation. This is just a flat line.

If the line we are looking for is flat; it stays at the same y-value the entire time. We see that  the y-value for this line of ours is -6. Therefore, the answer is C. y=-6.

Step-by-step explanation:

; ) BELIEVE IN YOURSELF!!!!!!!!!!!!!!!!!

Step-by-step explanation:

(AUB)' means they are all outside the set A and B so thats 0. Hope it helps

Explanation:

Let the 11 numbers be {a1, a2, ..., a11} such that a1 is the smallest and a11 is the largest. So, a1 < a2 < ... < a11. Furthermore, these numbers are consecutive.

If we add consecutive numbers to get a negative result, then each of the numbers must be negative. So every value in the set {a1, a2, ..., a11} is a negative value which makes it impossible to have a1+a2+...a11 be a positive sum.