Answer:
The 98% confidence interval for the mean amount spent on their child's last birthday gift is between $40.98 and $43.02.
Step-by-step explanation:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 24 - 1 = 23
98% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 23 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.98}{2} = 0.99[/tex]. So we have T = 2.5
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 2.5\frac{2}{\sqrt{24}} = 1.02[/tex]
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 42 - 1.02 = $40.98.
The upper end of the interval is the sample mean added to M. So it is 42 + 1.02 = $43.02.
The 98% confidence interval for the mean amount spent on their child's last birthday gift is between $40.98 and $43.02.
Read the following scenario, and then answer the question.
Juan assumes that the temperature of the hot tea cooling on his desk can be modeled with an exponential function like this one: T(t)=179(0.92)t. He bases his assumption on the following: The tea cools about 8% every minute. The tea's current temperature is around 179 degrees Fahrenheit.
Which explanation correctly addresses Juan's assumption?
He is incorrect. The tea will cool linearly since it cools at the same number of degrees every minute.
He is correct. The tea will cool exponentially since it cools at a percentage rate every minute.
He is incorrect. The tea will cool along the curve of a parabola since it cools at an increasing percentage rate every minute.
9514 1404 393
Answer:
(b) He is correct. The tea will cool exponentially since it cools at a percentage rate every minute.
Step-by-step explanation:
Newton's Law of Cooling says the change in temperature is proportional to the temperature. This relation gives rise to an exponential function describing the temperature.
In this description, the temperature referred to is the difference between the temperature of the object and the temperature of the environment to/from which heat is being transferred.
Juan is only partially correct. The function is exponential, but the temperature that should be used in his equation is not the temperature of the tea, but the temperature difference between the tea and his desk.
__
The curve is not linear and not parabolic, excluding the other answer choices.
question:
A sequence is defined by the recursive function f(n + 1) = –10f(n).
If f(1) = 1, what is f(3)?
3
–30
100
–1,000
the answer is 100
Answer:
100
Step-by-step explanation:
f(1) = 1
f(2) = -10×f(1) = -10 × 1 = -10
f(3) = -10×f(2) = -10 × -10 × f(1) = -10 × -10 × 1 = 100
f(n) = -10 to the power of n-1
Answer:
c - 100
Step-by-step explanation:
A number is selected at
random from each of the sets
£2,3,4} and {1, 3, 5}. Find the
Probability that the sum of the two numbers is greater than 3 but less than 7?
Answer:
0.4444 = 44.44% probability that the sum of the two numbers is greater than 3 but less than 7.
Step-by-step explanation:
A probability is the number of desired outcomes divided by the number of total outcomes.
A number is selected at random from each of the sets {2,3,4} and {1, 3, 5}.
The possible values for the sum are:
2 + 1 = 3
2 + 3 = 5
2 + 5 = 7
3 + 1 = 4
3 + 3 = 6
3 + 5 = 8
4 + 1 = 5
4 + 3 = 7
4 + 5 = 9
Find the probability that the sum of the two numbers is greater than 3 but less than 7?
4 of the 9 sums are greater than 3 but less than 7. So
[tex]p = \frac{4}{9} = 0.4444[/tex]
0.4444 = 44.44% probability that the sum of the two numbers is greater than 3 but less than 7.
Jill has 32 crayons. She loses 4 of the crayons. How many are left?
Answer:
the answer here is d
the answer is d
Answer:
28
Step-by-step explanation:
Total number of crayons = 32
Number of crayons lost = 4
Therefore, number of crayons she is left with is : 32 - 4 = 28
Working :
[tex]32\\04 - \\\overline{28}[/tex]
Use the expression 9(7 + 2x) to answer the following:
Part A: Describe the two factors in this expression. (4 points)
Part B: How many terms are in each factor of this expression? (4 points)
Part C: What is the coefficient of the variable term? (2 points)
Step-by-step explanation:
Part A:
The two factors in 9(7+2x) are 9 and 7+2x
Part B:
First term: 9
Second term: 7+2x
Part C:
9(7+2x)
Open bracket
63+18x
The coefficient is 18x
A. The two factors are 9 and (7+2x).
B. In first factor, only one term and in second factor , two terms i.e. 7 and 2x are present.
C. The coefficient of the variable term is 18.
Algebraic expression:Given expression is;
[tex]9(7+2x)[/tex]
In given expression, there are two factors fist is 9 and second one is [tex](7+2x)[/tex]
In first factor, only one term and in second factor , two terms i.e. 7 and 2x are present.
To find the coefficient of variable term, we have to to expand given expression.
[tex]9(7+2x)=63+18x[/tex]
The coefficient of the variable term is 18.
Learn more about the algebraic expression:
https://brainly.com/question/4344214
The data represent the results for a test for a certain disease. Assume one individual from the group is randomly selected. Find the probability of getting someone who tests negative, given that he or she did not have the disease.
The individual actually had the disease
Yes No
Positive 135 11
Negative 99 145
Answer:
0.9295 = 92.95% probability of getting someone who tests negative, given that he or she did not have the disease.
Step-by-step explanation:
A probability is the number of desired outcomes divided by the number of total outcomes.
In this question:
11 + 145 = 156 people did not have the disease.
Out of those, 145 tested positive. So
[tex]p = \frac{145}{156} = 0.9295[/tex]
0.9295 = 92.95% probability of getting someone who tests negative, given that he or she did not have the disease.
You are watching an airplane fly in the distance.The airplane is traveling at altitude of 8 kilometers How far is the airplane from your location?
How to find the surface area of a this cuboid
Answer:
40
Step-by-step explanation:
There are 6 sides. Four sides have 8 squares, 4 * 2, and the other 2 sides have 4, 2 * 2. 8 * 4 = 32, 4 * 2 = 8, 32 + 8 = 40
Joe bikes at the speed of 30 km/h from his home toward his work. If Joe's wife leaves home 5 mins later by car, how fast should she drive in order to overtake him in 10 minutes.
Answer:
45 mph
Step-by-step explanation:
This is a really good question to know the answer to. It is tricky and a bit indirect (which means you have to find something else before you can find the speed of the car.)
Let's keep track of what he does in the time allotted.
How far does Joe go in 5 minutes? That's the amount of time he's on the road before she is.
convert 5 minutes into hours. 5 minutes * 1 hour / 60 minutes = 1/12 of an hour
d = r*t
r = 30 km/hour
t = 1/12 hour
d = 30 km/hr * 1/12 hour = 2.5 km
Now she's about to start. She wants to catch him in 10 minutes
d = r*t
r = x mph
t = 10 minutes = 10 minutes * 1 hour * 60 minutes = 1/6 of an hour.
How far does he go in the 10 minute time?
d = 30 * 1/6 = 5 km
What is his total distance
5 km + 2.5 km = 7.5 km
Finally how fast does she need to go to catch him
d = 7.5 km
r = ? This is what you are trying to find
t = 1/6 of an hour
d = r*t
7.5 km = r * (1/6)hour divide by 1/6 hour
7.5 km // 1/6 hour = r
r = 7.5 * 6 = 45 mph
Which function has no horizontal asymptote?
Answer:
[tex]{ \tt{f(x) = \frac{x - 1}{3x} }}[/tex]
Answer:
c
Step-by-step explanation:
edge
a woman bought some large frames for
$12 each and some small frames for $5
each. If she bought 20 frames for $156
find how many of each type she bought.
Answer:
8 pairs of large glasses and 12 pairs of small ones
Step-by-step explanation:
Let's say the number of large frames she buys is l, and the number of small frames is s. She buys 20 frames of assorted sizes, but they can only be small or large. Therefore, s + l = 20.
Next, the total cost of large frames is 12 dollars for each frame. Therefore, the total cost for the large frames is equal to 12 * l. Similarly, the total cost for the small frames is equal to 5 * s. The total cost of all frames is equal to 156, so
12* l + 5 * s = 156
s + l = 20
In the second equation, we can subtract l from both sides to get
s = 20 - l
We can then plug that into the first equation to get
12 * l + 5 * (20-l) = 156
12 * l + 100 - 5*l = 156
subtract both sides by 100 to isolate the variable and its coefficient
12 * l - 5 * l = 56
7 * l = 56
divide both sides by 7 to isolate the l
l = 8
The woman buys 8 pairs of large glasses. The number of small glasses is equal to 20-l=20-8=12
Each of the 8 cats in a pet store was weighed. Here are their weights (in pounds): 6,6, 10, 6, 8, 7, 14, 12 Find the median and mean weights of these cats. If necessary, round your answers to the nearest tenth. Median: pounds Х X ? Mean: pounds
Answer:
Median: 7.5
Mean: 8.6
Step-by-step explanation:
Median = the average of the 2 middle numbers of the set in ascending order, 6, 6, 6, 7, 8, 10, 12, 14
(7+8)/2 = 2
Mean = the sum of the numbers divided by the number of values
6 + 6+ 6+ 7 +8 +10 +12 +14/8
69/8
8.625
Find the graph of the solution set of the following system of linear inequalities
Answer:
the graph looks like this:-
Step-by-step explanation:
for inequality 1
if we take x = 0 we get y = -4
and if we take y =0 we get x = 16
so we get 2 points (0, -4) and (16, 0) and the graph must pass thru these two.
now checking if the origin satisfies the inequality or not
take x and y = 0
0 + 0 is not greater than or equal to -16
so origin doesn't satisfy the inequality.
shade the graph on the side, of the line, opposite to where the origin is.
for inequality 2
if we take x = 0 we get y = 2
and if we take y =0 we get x = -⅔
so we get 2 points (0, 2) and (-⅔, 0) and the graph must pass thru these two.
the line should be a dotted line.
now checking if the origin satisfies the inequality or not
take x and y = 0
0 + 0 is less than 2
so origin satisfies the inequality.
shade the graph on that side of the line where the origin is.
[ red line shows graph 1 whereas the blue dotted line represents graph ]
A radioactive substance decays exponentially: The mass at time t is m(t) = m(0)e^kt, where m(0) is the initial mass and k is a negative constant. The mean life M of an atom in the substance is
[infinity]
M = âk â« te^kt dt.
0
For the radioactive carbon isotope, 14C, used in radiocarbon dating, the value of k is -0.000121. Find the mean life of a 14C atom.
Answer:
mean life = 8264.5 s
Step-by-step explanation:
k = - 0.000121
The relation is given by
[tex]m = mo e^{kt}[/tex]
Now, the mean life is the life time for which the sample retains.
The mean life is the reciprocal of the decay constant.
The relation between the mean life and the decay constant is
[tex]\tau =\frac{1}{k}\\\\\tau = \frac{1}{0.000121} = 8264.5 seconds[/tex]
Find m angle JRQ if m angle SRQ=166^ and m angle SRJ=110^
Answer:
[tex] \large{ \tt{❃ \: S \: O \: L \: U \: T \: I \: O \: N : }}[/tex]
[tex] \large{ \tt{❉ \: m \: \angle \:SRQ = m \: \angle \: SRJ\: + \: m \: \angle \:JRQ}}[/tex]
[tex] \large{ \tt{⟼ \: 166 \degree = 110 \degree + m \: \angle \: JRQ}}[/tex]
[tex] \large{ \tt{⟼ \: 166 \degree - 110 \degree = m \: \angle \: JRQ}}[/tex]
[tex] \boxed{ \large{ \tt{⟼ \: 56 \degree = m \: \angle \: JRQ}}}[/tex]
Our final answer is 56° . Hope I helped! Let me know if you have any questions regarding my answer! :)Please help I’m really stuck this is my last attempt
What is the mode for the set of data?
Ages
Stem Leaves
5 0, 4, 6
6 0, 2, 3, 4, 8, 8, 9
7 0, 2, 3, 4, 4, 4, 8, 9
8 4, 5, 6, 8
5|0 = 50 years old
33
68
4
74
Answer:
I THINK IT IS 74 NOT 4
I HOPE THIS HELPS!!!!!
find integer pairs for -18?
Answer:
Step-by-step explanation:
Factor pairs:
1, 18
2, 9
3, 6
A canning factory turns out 568 tins of jam on a certain day. How many tins will be produced in 297 working days?
The perimeter of a square and rectangle is the same. The width of the rectangle is 6cm and it's area is 16cmsquare less than the area of the square. Find the area of the square
Answer:
Area of square = 100 square cm
Step-by-step explanation:
Let the sides of a square be = a
Perimeter of a square = 4a
Let area of square = [tex]a^2[/tex]
Let the Length of rectangle be = [tex]l[/tex]
Given: width of the rectangle = 6 cm
Area of rectangle = length x breadth
Perimeter of rectangle and square is equal.
That is,
[tex]2(length + width) = 4a\\\\2(l + 6) = 4a\\\\l + 6 = 2a\\\\l = 2a - 6[/tex]
Therefore ,
Area of rectangle
[tex]= Length \times width \\\\= (2a - 6) \times 6\\\\=6(2a - 6)[/tex]
Given area of rectangle is 16 less than area of square.
That is ,
[tex]( 6(2a- 6) ) = a^2 - 16\\\\12a - 36 = a^2 - 16\\\\a^2 - 12a +20= 0\\\\a^2 - 2a -10a + 20 = 0\\\\a(a - 2) - 10(a - 2) = 0\\\\(a -10) ( a-2) = 0\\\\a = 10 , \ a = 2[/tex]
Check which value of 'a ' satisfies the equation:
[tex]\underline {when \ a = 2 }\\\\Length\ of \ rectangle \ l = 2a - 6 = 2 ( 2 ) - 6 = 4 - 6 = - 2. \\\\Length \ cannot \ be \ negative \ number. \\\\ \underline{ when \ a = 10 }\\\\Length \ of \ rectangle \ , l = 2a - 6 = 2 (10) - 6 = 20 - 6 = 14\\\\satisfies \ the \ conditions. \\\\Therefore , a = 10[/tex]
That is , side of the sqaure = 10
Therefore , area of the square = 10 x 10 = 100 square cm.
(2x4−7x3−6x2+23x−12)÷(x−4)
Answer:
[tex]\frac{23x-37}{x-4}[/tex]
Step-by-step explanation:
it is estimated that 50% of emails are spam emails. Some software has been applied to filter these spam emails before they reach your inbox. A certain brand of software claims that it can detect 99% of spam emails and the probability for a flase positive is 5%. What is the probability that an email is detected as spam
Answer:
0.52 = 52% probability that an email is detected as spam.
Step-by-step explanation:
Probability that an email is detected as spam:
99% of 50%(are spam).
5% of 100 - 50 = 50%(false positives, that is, e-mails that are not spam but are detected as spams).
What is the probability that an email is detected as spam?
[tex]p = 0.99*0.5 + 0.05*0.5 = 0.52[/tex]
0.52 = 52% probability that an email is detected as spam.
Complete the steps to solve the equation. 3x - 6(5x + 3) = 9x + 6 1. The distributive property 3x - 30x 18 = gr + 6 2 Combine like terms. -27x - 18 = 9x + 6 3. Addition property of equality: -18 = 36x + 6 4. Subtraction property of equality: -24 = 36x 5. Division property of equality I
Answer:
see below
Step-by-step explanation:
3x - 6(5x + 3) = 9x + 6
Distribute
3x -30x-18 = 9x+6
Combine like terms
-27x - 18 = 9x+6
Add 27x to each side
-27x+27x-18 = 9x+27x+6
-18 = 36x+6
Subtract 6 from each side
-18-6 = 36x+6-6
-24 = 36x
Divide by 36
-24/36 = 36x/36
Simplify
-2/3 = x
Answer:
[tex]\small \sf x = \frac{2}{-3} \\ [/tex]
Step-by-step explanation:
3x - 6(5x + 3) = 9x + 6.
Use the distributive property to multiply -6 by 5x + 3.
3x - 30x - 18 = 9x + 6
Combine 3x and -30x to get -27x.
-27x - 18 = 9x + 6
Subtract 9x from both sides.
-27x - 9x - 18 = 9x - 9x + 6
-36x - 18 = 6
Add 18 to both sides.
-36x - 18 + 18 = 6 + 18
-36x = 24
Divide both sides by -36.
[tex]\small \sf \frac{ -36x}{ -36} = \frac{24}{-36} \\ [/tex]
Reduce the fraction [tex]\frac{24}{-36} [/tex] to lowest terms by extracting and canceling out 12.
[tex]\small \sf x = \frac{2}{-3} \\ [/tex]
solve for the solution of each linear equation.
1. 3x+1=4
2. 7x-6=0
3. 4x-5=19
4. 9x+6=8
5. 8x-7=15
Answer:
no.1 answer 0
Step-by-step explanation:
3x + 1= 4
or; 3x = 4 - 1
or; x = 3 ÷ 3
x = 0
Movie Selections The Foreign Language Club is showing a three-movie marathon of subtitled movies. How many ways can they
choose 3 from the 17 available?
Answer:
Step-by-step explanation:
This is a beginning counting problem, or is it?
If order matters then the answer is
17P3 = 17! / (14!) = 17 * 16 * 15 = 4080
However if it does not matter then
17C3 = 17!/(3! * 14!)
680
Which ordered pair (a, b) is the solution to the given system of linear equations? 3a+b= 10 -4a-2b=2
(1,7)
(3, 1)
(11, -23)
(23, -11)
Hello,
answer C (11,-23)
[tex]\left\{\begin{array}{ccc}3a+b&=&10\\-4a-2b&=&2\end{array}\right.\\\\\\\left\{\begin{array}{ccc}6a+2b&=&20\\-4a-2b&=&2\end{array}\right.\\\\\\\left\{\begin{array}{ccc}3a+b&=&10\\2a&=&22\end{array}\right.\\\\\\\left\{\begin{array}{ccc}a&=&11\\b&=&10-3*11\end{array}\right.\\\\\\\left\{\begin{array}{ccc}a&=&11\\b&=&-21\end{array}\right.\\[/tex]
Answer: C. (11,-23)
Step-by-step explanation:
The control department of a light bulb manufacturer randomly picks light bulbs from the production lot every week. The records show that, when there is no malfunction, the defect rate in the manufacturing process (due to imperfections in the material used) is . When or more of the light bulbs in the sample of are defective, the control unit calls repair technicians for service.
Required:
a. Find the mean of p, where p is the proportion of defective light bulbs in a sample of 4400 when there is no malfunction.
b. Find the standard deviation of p.
Answer:
The answer is a
Step-by-step explanation:
why no one helping me please help please please please please please
Answer:
a) A
b) C and E
c) C, D and F
d) two
e) Equal
i need helpp pleaseee
Round 10,998 to nearest ten
Answer:
11,000
Step-by-step explanation:
2(2x + 4) + 2(x - 7) = 78. Determine the side lengths of this rectangle.
[tex]2(2x + 4) + 2(x - 7) = 78[/tex]
[tex]4x + 8 + 2x - 14 = 78[/tex]
[tex](4x + 2x) + (8 - 14) = 78[/tex]
[tex]6x - 6 = 78[/tex]
[tex]6x = 78 + 6[/tex]
[tex]6x = 84[/tex]
[tex]x = \frac{84}{6} [/tex]
[tex]x = 14[/tex]