The half-life of radioactive iodine is 60 days. How much of a 50-mg sample will be left in 40 days? Round your answer to the nearest tenth.

Answer:

CI =(0.333, 0.480)

Step-by-step explanation:

The formula for calculating the confidence interval is expressed as shown;

CI = p±Z * √p(1-p)/n±0.5/n

Z is the z-score at 90% confidence

p is the sample proportion

n is the sample size

Given n = 144, p = 0.4 and z-score at 90%  CI = 1.645 (from z table)

Substituting this values;

CI = p ± 1.645*√0.4(1-0.4)/144 ±0.5/n

CI = 0.4 ± 1.645*√0.4(0.6)/144 ± 0.5/144

CI = 0.4 ±1.645 * √0.24/144 ± 0.00347

CI = 0.4 ±1.645 * 0.04087± 0.00347

CI = 0.4±0.06723±0.00347

CI =(0.333, 0.480)

Answer:

1. slope = -x, Y-intercept = 2

2. slope = -1/3,Y-intercept = 2

3. slope = 5/2, Y-intercept = 2

4. slope = -2, Y-intercept = 1

5. slope = -3/4, Y-intercept = 2

Step-by-step explanation:

To find the slope and y-intercept you have to solve the equation. You only have to solve for 2 and 3. 1, 4, and 5 already have the equations solved. For questions 1, 4, and 5 the first number is the slope and the second number is the y-intercept. For questions 2 and 5 you have to solve the equations. You have to bring the y to the right side of the equation. to do that you subtract the y. Then you have to bring the number that was already on the right side of the equation to the left side. To do this you also have to subtract that number to bring it to the other side. Now you have to get the y by its self, and to do this you divide the equation. You divide both sides of the equation. Then you can get the slope and y-intercept.

Answer

187.5 ml/hr

Step-by-step explanation:

1500ml/8hrs=187.5ml/hr

Answer:

The answer is "[tex]y=\frac{c}{1+a}[/tex]".

Step-by-step explanation:

Given:

[tex]\bold{y=\frac{c}{1+ae^{-rx}}}[/tex]

For the y-intercept, the value x is =0

[tex]y=\frac{c}{1+ae^{-r \times 0}}[/tex]

[tex]y=\frac{c}{1+ae^{0}}[/tex]

[tex]\therefore e^0 = 1[/tex]

[tex]y=\frac{c}{1+a\times 1}}[/tex]

[tex]\boxed{y=\frac{c}{1+a}}[/tex]

Answer:

5 meters : 1 gallon

fuel efficiency of Car is 7 meters per gallons

Step-by-step explanation:

Given Tanya car goes 45 meters on 7 gallons.

In terms of ratio  of distance traveled and fuel consumed

45 meters : 7 gallons

since both 45 and 7 are multiple of 7 dividing both side by 7

45/7 meters : 7/7 gallons

5 meters : 1 gallon

Thus, fuel efficiency of Car is 7 meters per gallons.

Answer:

The 95% confidence interval for true average degree of polymerization is (431, 446).

Step-by-step explanation:

The data provided for the degree of polymerization for paper specimens for which viscosity times concentration fell in a certain middle range is:

S = {418, 421, 422, 422, 425, 429, 431, 434, 437,  439, 446, 447, 449, 452, 457, 461, 465}

Compute the sample mean and sample standard deviation:

[tex]\bar x=\frac{1}{n}\sum X=\frac{1}{7}\times 7455=438.5294\\\\s=\sqrt{\frac{1}{n-1}\sum (X-\bar x)^{2}}=\sqrt{\frac{1}{17-1}\times 3594.2353}=14.988[/tex]

As the population standard deviation is not provided use the t-statistic to compute the two-sided 95% confidence interval for true average degree of polymerization.

[tex]CI=\bar x\pm t_{\alpha/2, (n-1)}\cdot\frac{s}{\sqrt{n}}[/tex]

The critical value of the t is:

[tex]t_{\alpha /2, (n-1)}=t_{0.05/2, (17-1)}=t_{0.025, 16}=2.12[/tex]

*Use a t-table.

Compute the 95% confidence interval for true average as follows:

[tex]CI=438.5294\pm 2.12\cdot\frac{14.988}{\sqrt{17}}[/tex]

     [tex]=438.5294\pm 7.7065\\=(430.8229, 446.2359)\\\approx (431, 446)[/tex]

Thus, the 95% confidence interval for true average degree of polymerization is (431, 446).

Answer:

The answer is "[tex]= \frac{\pi}{8}(15-41n^2 )\\[/tex]".

Step-by-step explanation:

The radius = x

the value of height is= [tex]e^{-x}[/tex]

The Formula for  the volume by the shell method:

[tex]\bold{V= \int\limits^b_a {(2\pi\ rad)(height)} \, dx }[/tex]

   [tex]= 2\pi \int\limits^{In 16}_0 {xe^{-x}} \, dx\\\\\\= 2\pi {(e^{-x}[-x-1])}_{0}^{In 16}\\\\ = 2\pi {(\frac{1}{16} \times (15-41n^2 ))}\\\\ = \frac{\pi}{8}(15-41n^2 )\\[/tex]

Answer:

slope is undefined

Step-by-step explanation:

x = 4 is the equation of a vertical line parallel to the y- axis.

The slope of a vertical line is undefined

Answer:

Undefined

Step-by-step explanation:

If the line is strait up like x = 4 that means it is undefined.

Answer:

Going from up to down

Box #1=0

Box #2=3

Box #3=5

Step-by-step explanation:

Answer:

Step-by-step explanation:

Going from up to down

Box #1=0

Box #2=3

Box #3=5

Step-by-step explanation:

Hi there!!!

The answer is option A.

reason look in picture.

if you want to solve it just cross multiply it,

[tex]60x = 240000 \times 100[/tex]

or,

[tex]x = 24000000 \div 60[/tex]

and the answer would be 400000.

Hope it helps...

Answer:

H0: μ=2; Ha: μ>2

Step-by-step explanation:

The null hypothesis is the default hypothesis while the alternative hypothesis is the opposite of the null and is always tested against the null hypothesis.

In this case study, the null hypothesis is that adults were eating, on average, the recommended 2 cups of vegetables a day: H0: μ=2 while the alternative hypothesis is adults were eating, on average, more than the recommended 2 cups of vegetables a day Ha: μ>2.

Answer:

a) 4

Step-by-step explanation:

y = 3x

Plug it in: x - 2 (3x) = 10 --> x - 6x = 10 --> -5x = 10 --> x =  -2

Therefore: y = 3(-2) --> y = -6

x - y = -2 - (-6) = 4

Answer:

The principal must be = $8991.88

Step-by-step explanation:

Formula for compound interest is:

[tex]A = P(1 + \frac{r}{n})^{nt}[/tex]

Where A is the amount after 't' years.

P is the principal amount

n is the number of times interest is compounded each year.

r is the rate of interest.

Here, we are given that:

Amount, A = $15000

Rate of interest = 13 % compounded quarterly i.e. 4 times every year

Number of times, interest is compounded each year, n = 4

Time, t = 4 years.

To find, Principal P = ?

Putting all the given values in the formula to find P.

[tex]15000 = P(1 + \frac{13}{400})^{4\times 4}\\\Rightarrow 15000 = P(1 + 0.0325)^{16}\\\Rightarrow 15000 = P(1.0325)^{16} \\\Rightarrow 15000 = P \times 1.66817253\\\Rightarrow P = \dfrac{15000}{1.66817253}\\\Rightarrow P \approx \$8991.88[/tex]

So, the principal must be = $8991.88

The principal required is $ 8993.

Using the formula;

A = P(1 + r/n)^nt

Where;

P = principal = ?

r = rate = 0.13

n = Number of times the interest is compounded = 4

t = time = 4years

Amount = $15,000

15,000 = P(1 +  0.13/4)^4(4)

15,000 = P(1.668)

P = 15,000/1.668

P =$ 8993

Learn more: https://brainly.com/question/7558603

Answer:

G(2b) = 10b + 3

Step-by-step explanation:

To find G(2b), simply plug in 2b wherever there is an x in G(x).

G(x) = 5x + 3

G(2b) = 5(2b) + 3

G(2b) = 10b + 3

Answer:

3 + 10b maybe?

Step-by-step explanation:

Answer:

The percentage of college seniors with "Other" majors is 32%.

Step-by-step explanation:

The total number of college seniors surveyed is, N = 400.

The number of college seniors with "Other" majors is, n = 128.

The percentage of a value of x from N total is given as follows:

[tex]\text{Percentage of}\ x=\frac{x}{N}\times 100\%[/tex]

Compute the percentage of college seniors with "Other" majors as follows:

[tex]\text{Others}\%=\frac{n}{N}\times 100\%[/tex]

              [tex]=\frac{128}{400}\times 100\%\\\\=32\%[/tex]

Thus, the percentage of college seniors with "Other" majors is 32%.

Hi,

[tex]A=\frac{base_{1} +base_{2} }{2} *h\\\\A=(base_{1} +base_{2} ) *h *\frac{1}{2} \\\\A=(70ft + 130ft) * 50ft *\frac{1}{2} \\\\A=5000ft^{2}[/tex]

each bag covers 3000 ft²

[tex]N_{number of bags} = 5000ft^{2} / 3000ft^{2} \\\\N_{number of bags} = 1.6[/tex]

We need to purchase two bags fertilizer, but will use one and a half of them.

Have a good day.

Answer:

10 termites will destroy 0.000084kg of wood per week

Step-by-step explanation:

Convert milligram to kilogram

1.2mg=(1.2 / 1,000,000)kg

1.2mg=0.0000012kg

1 termite destroys=0.0000012kg per day

10 termites will destroy (per day) =0.0000012×10 termites per day

10 termites in one day will destroy=0.000012kg

There are 7 days in a week

Therefore,

10 termites will destroy=destruction per day × 7 days

=0.000012×7

=0.000084kg per week

Answer:

j/2+7= -12

(j+14)/2= -12

cross-multiply

j+14= -24

j= -38

Answer:

[tex]\boxed{j=-38}[/tex]

Step-by-step explanation:

[tex]\frac{j}{2} +7=-12[/tex]

Subtract 7 on both sides.

[tex]\frac{j}{2} +7-7=-12-7[/tex]

[tex]\frac{j}{2}=-19[/tex]

Multiply both sides by 2.

[tex]\frac{j}{2}(2)=-19(2)[/tex]

[tex]j=-38[/tex]

Answer:

The square root of one million is 1000 because 1000 x 1000 = 1,000,000

Answer:

ans1 9/11

ans2 8/52

it is because the reciprocol means the opposite of the the give value

Answer:

Step-by-step explanation:

a.

[tex] \frac{11}{9} [/tex]

Just flip the fraction, you will get:

[tex] \frac{9}{11} [/tex]

b.

[tex]5 \frac{1}{8} [/tex]

The first thing you have to do is that convert the mixed fraction into improper fraction.

To convert mixed fraction into improper fraction, you have to rewrite the denominator which is 8 , Thenafter you have to multiply 5 and 8 and then add 1

It would be:

[tex] \frac{5 \times 8 + 1}{8} [/tex]

[tex] = \frac{40 + 1}{8} [/tex]

[tex] = \frac{41}{8} [/tex]

Now , you have to flip it in order to get reciprocal:

[tex] = \frac{8}{41} [/tex]

Answer:

Step-by-step explanation:

The p value (probability of obtaining results as extreme the z score if null is true) is usually the value derived to make a conclusion and in this case the p value is 0.03

The level of significance is the value usually compared with the p value which is 0.05

The sample promotion is 65 out of 100 = 65/100 = 0.65

The sample size is the total number of consumers which is 100

The null value is usually the default value. The null value would assume that there is no difference in the proportions who prefer each type in the population. There are two preferences: 100/2 = 50- 0.5 for each preference.

Answer:

None of these choices are correct

Step-by-step explanation:

Law of exponents

3^(x+5) = 9^(-1)

3^(x+5) = (3²)^(-1)

3^(x+5) = 3^(-2)

Same base, same power or exponents

x+5 = -2

x = -2 -5

x = -7

Answer: There is sufficient evidence to conclude that the proportion of agenda-less meetings is greater than 45%.

Step-by-step explanation:

Given: [tex]H_0:p=0.45 \\ H_a:p>0.45[/tex]

The p-value for this hypothesis test is 0.025.

The level of significance is α=0.05

As p-value< α  ∵0.025< 0.05

[if p-value< α , we reject [tex]H_0[/tex]]

then, we reject the null hypothesis.

i.e. We have sufficient evidence to support the alternative hypothesis.

Hence, the correct statement is : There is sufficient evidence to conclude that the proportion of agenda-less meetings is greater than 45%.

Answer:

(x + 2)(x - 6)

Step-by-step explanation:

We are given the equation: x² - 4x - 12. Let's factor this.

First, look at the integer factor pairs of -12:

-1, 12

-2, 6

-3, 4

1, -12

2, -6

3, -4

We would like to find a pair whose sum is -4. Inspecting each pair, we realise that only the pair 2, -6 works because 2 + (-6) = -4.

Thus, our factors are:

x + 2    (from the 2)

x - 6     (from the -6)

The factored form of our given quadratic is:

(x + 2)(x - 6)

~ an aesthetics lover

Answer:

The lateral surface is 120  [tex]in^2[/tex], which agrees with the third answer option of the list.

Step-by-step explanation:

Notice that the prism has 5 equal lateral faces, which are all rectangles of eight 6". The width of the prisms can be obtained by using the fact that the perimeter of the pentagon is 20", which gives a side length of 20/5 = 4 " which is the same as the with of the lateral rectangles.

Then the lateral area of the prism is:

Lateral area= 5 (6" x 4") = 5 (24) =  120 [tex]in^2[/tex]

Answer:

Number:3.75

Equation:7 x-9=3(x+2)

Step-by-step explanation:

Let the number be x.

According to the question,

7 x-9=3(x+2)

7 x-9= 3 x+ 6

7 x- 3 x= 9+6

4 x= 15

x=15/4

x=3.75

If you verify the answer you will get,

11.25=11.25

Thank you!

Answer: 0.0899.

Step-by-step explanation:

Given: CNNBC recently reported that the mean annual cost of auto insurance is 1048 dollars, the standard deviation is 282 dollars.

Sample size : n= 55

Let [tex]\overline{X}[/tex] be the sample mean.

The probability that a sample of size n =55 is randomly selected with a mean less than 997 dollars:

[tex]P(\overline{X}<997)=P(\dfrac{\overline{X}-\mu}{\dfrac{\sigma}{\sqrt{n}}}<\dfrac{997-1048}{\dfrac{282}{\sqrt{55}}})[/tex]

[tex]=P(Z<-1.3412)\ \ \ [Z=\dfrac{\overline{X}-\mu}{\dfrac{\sigma}{\sqrt{n}}}]\\\\=1-P(Z<1.3412)\\\\=1-0.9101\ \ \ \ [\text{By z-table}]\\\\ =0.0899[/tex]

Hence, the required probability = 0.0899 .

Answer: A. [tex]x\geq21\dfrac{2}{3}[/tex] .

Step-by-step explanation:

The given inequation: [tex]81-1\dfrac{1}{5}x\leq55[/tex]

[tex]\Rightarrow\ 81-\dfrac{6}{5}x\leq55[/tex]

Multiplying 5 on both the sides, we get

[tex]5(81-\dfrac{6}{5}x)\leq5\times55\\\\\Rightarrow\ 405-6x\leq275\\\\\Rightarrow\ 6x\geq405-275\\\\\Rightarrow\ 6x\geq130\\\\\Rightarrow\ x\geq\dfrac{130}{6}\\\\\Rightarrow\ x\geq\dfrac{65}{3}\\\\\Rightarrow\ x\geq21\dfrac{2}{3}[/tex]

Hence, the inequality for x is [tex]x\geq21\dfrac{2}{3}[/tex] .

So, the correct option is A. [tex]x\geq21\dfrac{2}{3}[/tex] ..

Answer:

  1.2b

Step-by-step explanation:

When we say, "a number that is 20% greater than b," we're talking about a number that is ...

  b + 20%×b

  = b + 0.20b

  = b(1 + 0.20)

  = 1.2b