Answer:
You should expect her to be wrong 32 times.
Step-by-step explanation:
For each forecast that she makes, there are only two possible outcomes. Either she is correct, or she is not. The probability of she being correct on a forecast is independent of other forecasts. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
The expected value of the binomial distribution is:
[tex]E(X) = np[/tex]
0.8 chance of being correct.
So 1 - 0.8 = 0.2 change of being wrong, which means that [tex]p = 0.2[/tex]
160 forecasts:
This means that [tex]n = 160[/tex]
How many of these times would you expect she is wrong?
[tex]E(X) = np = 160*0.2 = 32[/tex]
You should expect her to be wrong 32 times.
Michelle went shopping for some clothes and found a pair of slacks that cost
twice as much as a shirt that she liked. If the total, before tax, for the pair of
slacks and the shirt was $22.50, how much was the shirt, before tax?
Answer:
The sirt cost $7.5 before tax.
Step-by-step explanation:
Since the pair of slacks cost twice as much as the shirt, we have:
slacks = 2*shirt
And the total purchase was $22.5, so we have:
slacks + shirt = 22.5
We can create a system of equations such as:
slacks = 2*shirt
slacks + shirt = 22.5
If we apply the first formula on the second we can solve for the value of the shirt, we have:
2*shirt + shirt = 22.5
3*shirt = 22.5
shirt = 22.5/3 = 7.5
So the slacks cost:
slacks = 2*7.5 = 15
the perimeter of a circle is 132 calculate its diameter
Answer:
42
Step-by-step explanation:
The perimeter of circle is same as it’s circumference.
Circumference = π * D
132 = 22/7 * D
22D = 7 * 132
22D = 924
D = 924/22
D = 42
Answer:
42.0
Step-by-step explanation:
For this question we are given the circumference of a circle which is 132 and we are asked to find diameter of the circle. We need to utilise one important formula which the circumference of a circle formula
⇒ Circumference of a circle = π × d
We need to make 132 equal to the circumference of a circle formula so then we can work out the diameter by forming an equation to solve for the diameter so,
⇒ Form the equation
→ π × d = 132
⇒ Divide both sides by π to isolate d
→ d = 42.0169049763
The diameter of the circle with a perimeter of 132 is 42.0 to 1 decimal place
Mr. Whittaker’s science class uses tide gauges to measure annual variations in water levels at different parts of a river, and then compares those variations to the average annual trend. Matea recorded that the water level in one part of the river fell 1.05 millimeters per year for 2.48 years. This data will be compared to the average annual trend, which shows the water level rising 1.8 mm/year. Which number represents the rate at which the water level fell? Which number should the rate be multiplied by to find the total variation in water level?
This question is not complete because is lacks the options for each question.
Complete question
mr. whittaker’s science class uses tide gauges to measure annual variations in water levels at different parts of a river, and then compares those variations to the average annual trend. matea recorded that the water level in one part of the river fell 1.05 millimeters per year for 2.48 years. this data will be compared to the average annual trend, which shows the water level rising 1.8 mm/year.
1) Which number represents the rate at which the water level fell?
a. -1.05 mm/year
b. -1.8 mm/year
c. -2.48 years
d. -2.48 mm/year
2) Which number should the rate be multiplied by to find the total variation in water level?
a. 1.05 mm/year
b. 1.8 mm/year
c. 2.48 years
d. 2.48 mm/year
Answer:
1) Which number represents the rate at which the water level fell?
a. -1.05 mm/year
2) Which number should the rate be multiplied by to find the total variation in water level?
c. 2.48 years
Step-by-step explanation:
Total Variation in the water level is calculated by multiplying the rate at which the water level and number or years at which the rate of the water level fell
From the question, we can see that the rate at which the water level fell is -1.05 mm/year and number of years at which the water level fell is 2.48mm
Hence,Total Variation in the water level is calculated as
-1.05 mm/year × 2.48 years
Total variation in the water level = -2.604mm
Answer:
Which number represents the rate at which the water level fell?
-1.05 mm/year
Which number should the rate be multiplied by to find the total variation in water level?
2.48 years
Step-by-step explanation:
At 7:00 A.M., Alicia pours a cup of tea whose temperature is 200°F. The tea starts to cool to room temperature (72°F). At 7:02 A.M. the temperature of the tea is 197°F. At 7:15 A.M. the temperature of the tea is 180°F. Alicia will drink the tea when its temperature is 172°F.
Part A
Which of the following shows an exponential cooling equation that models the temperature of the tea?
A. y = 72(0.989)x + 128
B. y = 128(0.989)x + 72
C. y = 200(0.989)x + 72
D. y = 128(0.989)x + 200
Part B
When can Ella drink the tea?
Ella can drink the tea after
7:22
7:18
Answer:
Part A
The most correct option is;
b. y = 128(0.989)x + 72
Part B
Ella can drink the tea after 7:22
Step-by-step explanation:
Here we have the temperature variation with time given in an exponential equation as follows;
Let the temperature at time x (in minutes) = y
Therefore, y = a × mˣ + b
Where:
b = Shift of the curve or the limit value of the decreasing exponential function as x → ∞
When y = 200, x = 0
Therefore. 200 = a × m⁰ + c = a + c
We note that c is the shift of the graph, the value upon which temperature increases = final temperature = 72°F
Hence a = 200 - 72 = 128°F
When y = 197, x = 2 minutes
Therefore, 197 = 128·m² + 72 =
m² = (197 - 72)/128 = 125/128
m = √(125/128) = 0.98821
Hence the exponential equation of cooling is presented in the following equation;
y = 128 × (0.98821)ˣ + 72
Therefore, the most correct option is b. y = 128(0.989)x + 72
Part B
When the temperature is 172°F we have;
172 = 128 × (0.989)ˣ + 72
∴ (0.989)ˣ = (172 - 72)/128 = 100/128 = 25/32
log(0.989)ˣ = log(25/32)
x·log(0.989) = log(25/32)
x = log(25/32)/log(0.989) = 22.32 minutes
Hence Ella can drink the tea after 7:22.
need help asap will mark brainliest
Answer:
1725 ft²
Step-by-step explanation:
[tex]\frac{50+65}{2} *30[/tex] = [tex]\frac{115}{2} *30= 57.5*30 = 1725[/tex]
Answer:
1,950 ft
Step-by-step explanation:
it is a compound shape, thus it is made up of a square and a triangle
you can find the area of the square by 30 x 50 and the area of the triangle by 30 as the height and 65 - 50 as the base, and when you add it together you get 1,950
find the area of the kite brainly
Answer:
The area is 128.605[tex]meters^2[/tex]
Step-by-step explanation:
The formula for the area of a triangle is :[tex]\frac{base*height}{2}[/tex]
To work this out you would first have to divide the shape into 4 smaller triangles.
Then we are going to first calculate the area of on the bottom triangles. To do this we would multiply the base of 8.5 and the height of 10.2, this gives you 86.7[tex]meters^{2}[/tex]. Although you would normally divide the answer by 2, as there are 2 identical triangles that is not necessary.
Now that we know the area of the bottom triangles we can now work out the top triangles. You can do this by multiplying the base op 8.5 by the height of 4.93, this gives you 41.905[tex]meters^2[/tex].
To work out the total area of this shape you would simply add the areas of 86.7 and 41.905, this would gives you [tex]128.605meters^2[/tex]. This is because we first broke the shape down so you could work out the area of each individual area, however to work out the total all the areas must be added up.
1) Divide the shape into 4 smaller triangles.
2) Multiply 8.5 by 10.2.
[tex]8.5*10.2=86.7meters^2[/tex]
3) Multiply 8.5 by 4.93.
[tex]8.5*4.94=41.905meters^2\\[/tex]
4) Add 86.7 and 41.905.
[tex]86.7+41.905=128.605meters^2[/tex]
Hilda is taking out an $11,000 personal loan that she will repay in 5 years. If she receives a 10% interest rate, her monthly payments will be $233.72. If she receives and 18% interest rate her monthly payments will be $279.33. How much less interest will Hilda pay if she qualifies for the lower interest rate? *
Answer:
Hilda would pay $ 2,736.60 less interest
Step-by-step explanation:
The total interest payment is the total repayments for 5 years less the initial loan amount
If the interest rate is 10% Hilda repays $233.72 for 5 years multiplied by 12 months:
total repayment=$233.72*5*12=$ 14,023.20
Interest =$14,023.20-$11,000.00=$3.023.20
If the interest rate is 18% Hilda repays $279.33 for 5 years multiplied by 12 months:
total repayment=$279.33*5*12=$ 16,759.80
Interest =$16,759.80 -$11,000.00=$5759.8
Difference in interest payments=$5759.8 0-3.023.20=$ 2,736.60
Eva is 29 years old and has 2 children, ages 3 and 5. She makes 48,500 a year. Eva decides to buy a 400,000 10-year term policy then renew the policy for another ten years afterwards. To renew the policy the insurance company charges an extra 40% to her premium rate.
Answer:
Eva would have been better off selecting the 20-year term policy.
Step-by-step explanation:
Base on the scenario been described in the question, Eva would have been better off selecting the 20-year term policy. This reason is because assuming Eva bought the 20-year term policy, she wont be paying the new charge of extra 40% to her premium rate, compared to when she bought the 10-year term policy then renew the policy for another ten years.
Eva's best option would be to buy on a 20-year policy. This is better because she is able to evade the additional, 40% to her premium rate.
Insurance Premium;Premiums are percentages of the cost value charged by the insurance company for their services and benefits.
If she pays, 400,000 in ten years, this means she pays 40,000 each year.Upon renewal, she'll have to 40% more and her new premium will be; 56,000.Read more on insurance premium;
https://brainly.com/question/9696972
If the probability of rain is 0.75, the probability of fog is 0.25, and the probability of rain and fog is 0.25, what is the probability of rain or fog?
Answer:
[tex]P(A \cup B) = 0.75[/tex]
Step-by-step explanation:
There are two scenarios:
A - Rain
B - Fog.
The probability of rain or fog is determined by the Addition Rule, given that A and B are not mutually excluyent:
[tex]P(A\cup B) = P(A) + P(B) - P(A\cap B)[/tex]
[tex]P (A\cup B) = 0.75 + 0.25 - 0.25[/tex]
[tex]P(A \cup B) = 0.75[/tex]
Can someone help me!!
ASAP
Answer:
It would be 30
Step-by-step explanation:
6*5=30
A and B are vertical angles. If m A = (4x + 14) and m B = (5x – 5)º,
then find the measure of A
Vertical angles are equal/congruent
4x+14=5x-5
X=19
4(19)+14= 90
Angle A= 90
PLEASE PLEASE HELP ME ! 12 DAYS OF SCHOOL LIKE AND IM BEHINDDDDD
Answer:
The answer to the first one is A, the answers to the second one are 750, 250, 625, and 325, respectively.
Step-by-step explanation:
5/16 = 20/x
5x = 320
x = 64
30/80 = 3/8
10/80 = 1/8
25/80 = 5/16
15/80 = 3/16
3/8*2000 = 750
1/8*2000 = 250
5/16*2000 = 625
3/16*2000 = 325
Clara slept for a total of 126 hours over the cousrve of two weeks.If she sleeps for the same amount of each time each night,how many hours does she sleep per night?
Answer:
9
Step-by-step explanation:
Answer:
9 hours per night
Step-by-step explanation:
Assuming a week is 7 days
7 * 12 = 14 days
126/14=9
She slept 9 hours per night
simplify (2x+1) (x+3)
The points (0, 1), (1, 5), (2, 25), and (3, 125) are on the graph of a function. Which equation represents that function?
Answer:
Hello there I would love to assist but could you give me a little more info I think I know the answer but I want to make sure I got it 100% correct unless you cant give me more info ill just tell you what I think it is but if u can give me more info before I give u the answer to make sure its correct would be appreciated
Step-by-step explanation:
Answer:
D, f(x)=5x
got it right
hello I don't know how to do this, can somebody explain me? Graph the linear function w(x)= 3/5x+2
Answer:
okay so u have a graph
u go to the center 0,0
u go up 2 places
then up 3 ove to the left 5
the repeat that step
u get it
Step-by-step explanation:
Simplify the expression. Assume that all variables are positive. Exponents in simplified form should all be positive
Answer:
5
Step-by-step explanation:
We know that a^b^c = a^ (b*c)
1/25 ^(-2/3* 3/4)
1/25^ (-2/4)
1/25 ^ -1/2
Rewriting 1/25 as 5^-2
5^-2 ^-1/2
Again a^b^c = a^ (b*c)
5^(-2*-1/2)
5 ^ 1
5
Read the word problem below. Jill had $90. She bought a skirt that normally costs $42 but was on sale for half price. She also bought a T-shirt that was $8 off its regular price. Before sales tax, the total cost of the clothes was $31. What was the regular price of the T-shirt? What question is being asked in this word problem? What is the regular price of the skirt? How much money does Jill have left? How much does the T-shirt normally cost? What is the amount Jill pays in sales tax?
Answer:
What was the regular price of the T-shirt?
$18What question is being asked in this word problem?
what is the regular cost of the t-shirt purchased by Jill.What is the regular price of the skirt?
$42How much money does Jill have left?
without considering sales tax, Jill has $90 - $31 = $59 left.If I use the sales tax from where I live, the sales tax = $1.86, so the money that Jill will have left = $59 - $1.86 = $57.14How much does the T-shirt normally cost?
$18 (same as question 1)What is the amount Jill pays in sales tax?
since you do not include the sales tax % in the question, I will simply use the sales tax from where I live = $31 x 6% = $1.86Step-by-step explanation:
skirt $21
t-shirt = p - $8
before sales tax, total cost was $31
$21 + p - $8 = $31
p = $18
pls pls pls pls pls pls pls pls pls pls help
an airplane takes off from an airport at 11 am. fifteen minutes later, its shadow is 360000 feet away from the take off point and its altitude is 24000 ft. what is the exact distance the plane traveled in 15 minutes
Answer:
what grade are you in so i can help
Step-by-step explanation:
A farmer picks 242 apples on monday and 118 apples on tuesday on wednesday she sells 109 of the apples at the market. Which equation can be used to find a, the number of apples the farmer has left?
Answer:
Step-by-step explanation:
The apples picked on Monday and Tuesday = 242 + 118 = 360
Apples sold on Wednesday = 360 - 109 = 521
Number of apples left = 251
Equation used: (242 + 118) - 109
Mrs. Dominguez asked her students to plot the number of books they read over the summer.
Using the dot plot, how many students read two books?
1
2
3
6
Answer:
6
Step-by-step explanation:
Answer:
6 students read 2 books
PLZ HURRY I'M GOING TO GET A LOT OF QUESTION S
What is the surface area of the composite figure shown? 107 square feet 172 square feet 279 square feet 321 square feet
Answer:
it is 279 square feet
Step-by-step explanation:
Answer:
279 sq. feet
Step-by-step explanation:
got the question correct
Edg.
Terrence and Lee were selling magazines for a charity. In the first week, Terrance sold 30% more than Lee. In the
second week, Terrance sold 8 magazines, but Lee did not sell any. If Terrance sold 50% more than Lee by the end of the
second week, how many magazines did Lee sell?
Choose any model to solve the problem. Show your work to justify your answer.
Please explain I don’t understand how to solve this problem.
Lee sold 40 magazines
Step-by-step explanation:
Equation Model:
Let m be the number of magazines Lee sold.
150%-130%=20%, so if 0.2m=8 then m=40
Let me show another way: In the image above 20% is equal to 8 so if we use 8 and 20% and try to reach our way up to 100% (How much Lee sold in total) then we will get our answer.
20%=8
40%=16
60%=24
80%=32
100%=40
Therefore Lee sold 40 magazines.
Hope that makes sense! If you have any more questions or need further clarification then please comment down below or message me! Good luck!
What is the greatest common factor if 9 and 15
Answer:
3
Step-by-step explanation:
It is three because 3×5 is 15 and 3×3 is 9 so the greast common factore is 3.
ACT scores are normally distributed and from 2015 to 2017, the mean was 20.9 with a standard deviation of 5.6. A perfect score is 36. What percentage of the testers scored a perfect score?
Question 4 options:
0.46%
0.35%
99.65%
99.64%
Using the normal distribution, it is found that 0.35% of the testers scored a perfect score.
Normal Probability DistributionThe z-score of a measure X of a normally distributed variable with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex] is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The z-score measures how many standard deviations the measure is above or below the mean. Looking at the z-score table, the p-value associated with this z-score is found, which is the percentile of X.In this problem, the mean and the standard deviation are given, respectively, by:
[tex]\mu = 20.9, \sigma = 5.6[/tex]
The proportion of scores above 36(perfect scores) is given by one subtracted by the p-value of Z when X = 36, hence:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{36 - 20.9}{5.6}[/tex]
Z = 2.7
Z = 2.7 has a p-value of 0.9965.
1 - 0.9965 = 0.0035 = 0.35.%.
Hence, 0.35% of the testers scored a perfect score.
More can be learned about the normal distribution at https://brainly.com/question/24663213
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Find the volume of the cone khan academy
Answer:
V= 1/3 pi*r^2*
Step-by-step explanation:
The reason the volume of a cone involves using the fraction 1/3, is because it takes three cones to fill up a cylinder. So, if the volume of a cylinder is pi*r^2*h, and a cone is 1/3 the size, then the volume of a cone(which uses the same formula) has to have the 1/3rd in front.
what’s the answer for this
Answer:
Area of parallelogram A = base x height = 2 x 1 = 2 (in2)
Hope this helps
:)
A sports shop buys tents for $260 less 25% for buying more than 30 tents. The store operates on a markup of 30% of the sale price and advertises that all items are sold at a discount of 20% of the regular price. What is the regular price of the tents?
Answer: $253.50
Step-by-step explanation:
Markup = 30% of sale price
Store purchase price = (100% - 25%) × 260
Store purchase price = 75% × 260
Store purchase price = 0.75 × 260
Store purchase price = $195
Regular selling price = markup × purchase price
Markup = 30% of purchase price (100+30)%
Regular selling price :
1.30 × $195 = $253.50
Which statement about the parabola is not true?A. The focus lies on the axis of symmetry.B.The directrix of the parabola is parallel to the axis of symmetry.C. Each point on the parabola is equidistant from the directrix and the focus
Answer:
Option B
The directrix of the parabola is parallel to the axis of symmetry
Step-by-step explanation:
The directrix of the parabola is not parallel to the axis of symmetry. It is as a matter of fact, perpendicular to it.
A parabola is actually a set of points that are equidistant from a given point, the focus, and a given line the directrix.
The axis of symmetry is a line that divides the parabola into two equal halves and it always passes through the focus.
The directrix of the parabola is always perpendicular to this axis of symmetry as they always intersect at right angles.
We want to see which one of the given statements is false. We will see that the false one is B: "The directrix of the parabola is parallel to the axis of symmetry"
So in a parabola, we define the axis of symmetry as the vertical line that divides the parabola in two equal parts.
For a general parabola:
y = a*x^2 + b*x + c
The line of symmetry is at:
x = -b/2a
While we know that in a parabola the directrix is a horizontal line.
So the axis of symmetry and the directrix are perpendicular lines.
Then the statement that is false is B: "The directrix of the parabola is parallel to the axis of symmetry"
If you want to learn more, you can read:
https://brainly.com/question/3283347
Determine if Ginny factored correctly. If not, explain
where she made an error.
Answer:
The answer is A
Step-by-step explanation:
