Answer:
a) The mean is 10 and the variance is 0.0625.
b) 0.6826 = 68.26% probability that the mean time of the visitors is within 15 seconds of 10 minutes.
c) 10.58 minutes.
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
Normally distributed with a mean of 10 minutes and a standard deviation of 2 minutes.
This means that [tex]\mu = 10, \sigma = 2[/tex]
Suppose 64 visitors independently view the site.
This means that [tex]n = 64, = \frac{2}{\sqrt{64}} = 0.25[/tex]
a. The expected value and the variance of the mean time of the visitors.
Using the Central Limit Theorem, mean of 10 and variance of (0.25)^2 = 0.0625.
b. The probability that the mean time of the visitors is within 15 seconds of 10 minutes.
15 seconds = 15/60 = 0.25 minutes, so between 9.75 and 10.25 seconds, which is the p-value of Z when X = 10.25 subtracted by the p-value of Z when X = 9.75.
X = 10.25
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{10.25 - 10}{0.25}[/tex]
[tex]Z = 1[/tex]
[tex]Z = 1[/tex] has a p-value of 0.8413.
X = 9.75
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{9.75 - 10}{0.25}[/tex]
[tex]Z = -1[/tex]
[tex]Z = -1[/tex] has a p-value of 0.1587.
0.8413 - 0.1587 = 0.6826.
0.6826 = 68.26% probability that the mean time of the visitors is within 15 seconds of 10 minutes.
c. The value exceeded by the mean time of the visitors with probability 0.01.
The 100 - 1 = 99th percentile, which is X when Z has a p-value of 0.99, so X when Z = 2.327.
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]2.327 = \frac{X - 10}{0.25}[/tex]
[tex]X - 10 = 2.327*0.25[/tex]
[tex]X = 10.58[/tex]
So 10.58 minutes.
find the value of z, secant and tangent angles
Answer:
z = 110
Step-by-step explanation:
The measure of an angle created by the intersection of two secants outside a circle is half the difference of the angles it intercepts. In this it would be:
2x + 15 = 1/2 * (10x + 20 - 80)
We can now solve:
4x + 30 = 10x - 60
30 = 6x - 60
6x = 90
x = 15
This means the values of 10x + 20 is 10(15) + 20, which is 170.
Now, we can add up all the arcs in a circle, which sum to 360 degrees:
360 = z + 170 + 80
360 = z + 250
z = 110
Answer:
[tex]A)\ \ z = 110[/tex]
Step-by-step explanation:
One is given a circle with two secants. Please note that a secant is a line that intersects a circle in two places. The secant exterior angle theorem states that when two secants intersect each other outside of a circle, the measure of the angle formed is half the of the positive difference of the intersecting arcs. One can apply this theorem here by stating the following:
[tex]2x+15=\frac{(10x+20)-(80)}{2}[/tex]
Simplify,
[tex]2x+15=\frac{(10x+20)-(80)}{2}[/tex]
[tex]2x+15=\frac{10x-60}{2}[/tex]
[tex]2x+15=5x-30[/tex]
Inverse operations,
[tex]2x+15=5x-30[/tex]
[tex]15=3x-30[/tex]
[tex]45=3x[/tex]
[tex]15=x[/tex]
Substitute this value into the equation for one of the intersecting arcs to find the numerical value of that intersecting arc:
[tex]10x+20\\x = 15\\\\10(15) + 20\\= 150 + 20\\= 170[/tex]
The sum of all arc measures in a circle is (360) degrees. One can apply this here by stating the following:
[tex]80 + 170 + z = 360[/tex]
Simplify,
[tex]80 + 170 + z = 360[/tex]
[tex]250 + z = 360[/tex]
Inverse operations,
[tex]250 + z = 360[/tex]
[tex]z = 110[/tex]
Find the answer for x and y
Answer:
x = 57
y = 57
Step-by-step explanation:
because of the two parallel lines :
41+y+8+74 = 180 add like terms
y + 123 = 180 subtract 123 from both sides
y = 57
x - 3 + 41 + y + 8 = 180 because they make a straight line
x + y + 46 = 180
x + 57 + 46 = 180
x + 123 = 180 subtract 123 from both sides
x = 57
Four- sevenths of the children in class earned A's on the last math test. 18 children did not earn an A. How many earned A's? SHOW ALL WORK!!!
Answer: 24 people earnt As
Step-by-step explanation:
1. We know that 18 people are the other 3/7 of the class
2. We first find out 1/7, which is calculated by dividing 3/7 by 3, which is 18 / 3 so 6
3. We can then find 4/7 by multiplying the amount of 1/7 by 4, so 6 x 4 = 24
There is a circle with a center of 0,0 on a coordinate plane. There is one point on the circle's circumference in which the x:y ratio is 3:1. What is a possible coordinate?
Answer:
(3, 1)
Step-by-step explanation:
A circle with radius √10 and centre at (0, 0) will have a point (3, 1) on its circumference.
A chef is going to use a mixture two different brands of Italian dressing the first spring and days 5% vinegar the second brain contains 15% vinegar the sheriff wants to make 390$ ml addressing that is 9% vinegar how much of each brand should she use
I guess the chef is making the mixture for the sheriff... Let x be the amount of dressing with 5% vinegar that is required, and y the amount of 15% vinegar dressing (both amounts in mL).
The sheriff wants 390 mL of the mixed dressing, so that
x + y = 390
x mL of the 5% dressing contains 0.05x mL of vinegar, while y mL of the 15% dressing contains 0.15y mL of vinegar. The resulting mixture should have a concentration of 9% vinegar, so that it contains 0.09 (390 mL) = 35.1 mL of vinegar. This means
0.05x + 0.15y = 35.1
Solve for x and y :
y = 390 - x
0.05x + 0.15 (390 - x) = 35.1
0.05x + 58.5 - 0.15x = 35.1
23.4 = 0.10x
x = 234
y = 156
An organization consists of 8,684 employees. They decided to conduct a survey about their new vacation policies. The organization surveyed 884 of their employees and found that 36% of those surveyed disliked the new vacation policies. Assuming a 95% confidence level, which of the following statements holds true?
Answer:
A. As the sample size is appropriately large, the margin of error is ±0.032.
Step-by-step explanation:
The margin of error is ±0.032 and the sample size is appropriately large. Therefore, the correct option is A.
Solve the inequality (help pls)
Answer:
B
Step-by-step explanation:
(-2/3x)-10<1/3
(-2/3x)<1/3+10
(-2/3x)<31/3
x>-31/2, -31/2=-15 (1/2), x> - 15 (1/2)
The table and the Circle Chart shown display the percentage of dogs in seven different groups of dog breeds in a dog competition.
How does the Circle Graph misrepresent the data in the table?
A. The percentages do not add up to 100.
B. The size of the section representing the Non-Sporting group is smaller than the section that represents Herding group.
C. The number of regions in the graph is not correct for the data.
D. One of the breeds in the table is not represented in the Circle Chart.
Answer:
a
Step-by-step explanation:
Answer:
Incorrect, it's actually B.
Step-by-step explanation:
Look at the Non-Sporting Group and Herding Group. The sizes of the slices are different (NSG being smaller than HG)
brainliest to correct
Answer:
27
Step-by-step explanation:
Answer:
27
Step-by-step explanation:
-9 × -3
= 27
Note: When you multiply two integers with same sign, then their product is positive.
IF A= -35 , B = 10 , C= -5 verify that:-
a x (b+c) = a x b + a x c
Plz tell
Answer:
see below
Step-by-step explanation:
a x (b+c) = a x b + a x c
Let A= -35 , B = 10 , C= -5
-35 * ( 10 -5) = -35 *10 + -35 * -5
-35 *(5) = -350 + 175
-175 = -175
Help!!
A.) find f^-1 and use it to evaluate: f^-1(12)
B.) write a formula for the function g(x) that results when the parent function: f(x) = x^3 is vertically stretched by a factor of three, shifted to the left by 4 units and shifted down by 5 units
Answer:
Step-by-step explanation:
y = x³
x = ∛y
Switch x and y:
y = ∛x
f⁻¹(x) = ∛x
f⁻¹(12) = ∛12 ≅ 2.29
check:
x = 2.29
f(x) = 2.29³ ≅ 12
What are the odds IN FAVOR of picking a red marble from a bag of 10 green marbles, 10 yellow marbles, and 5 red marbles?
Answer:
there is a 20% chance of getting a red marble
Step-by-step explanation:
Answer:
there is a 1/5 percent chance or 20%
Step-by-step explanation:
Hope this helps!
How to solve this question. I need to show my work for this question.
A cookie recipe calls for 3 eggs and makes 4 dozen cookies.
a). How many cookies could you make with a dozen eggs?
b). How many eggs would you need to make 18 dozen cookies?
Step-by-step explanation:
Recall that 1 dozen = 12 so 4 dozen cookies has a total of 48 cookies. We are going to use the following ratios to solve the problem:
[tex]\left(\dfrac{3\:\text{eggs}}{48\:\text{cookies}}\right)[/tex] and [tex]\left(\dfrac{48\:\text{cookies}}{3\:\text{eggs}}\right)[/tex]
a) [tex]12\:\text{eggs}×\left(\dfrac{48\:\text{cookies}}{3\:\text{eggs}}\right) = 192\:\text{cookies}[/tex]
b) 18 dozen cookies = 216 cookies
[tex]216\:\text{cookies}×\left(\dfrac{3\:\text{eggs}}{48\:\text{cookies}}\right) = 13.5\:\text{eggs}[/tex]
2. What is the number 643,581 rounded off
to the thousands place?
(1) 640,000
(2) 643,000
(3) 643,600
(4) 644,000
(5) 644,600
Answer:
(4) 644,000
Step-by-step explanation:
643,581
The 3 is in the thousands place
We look at the hundreds place
5
It is 5 or greater so we round the thousands place up 1
644000
what fraction of 1 day is 48 minutes
Answer:
48 ÷ 60 = 4/5
Step-by-step explanation:
4/5 is the answer
Answer:
[tex]\frac{1}{30}[/tex]
Step-by-step explanation:
We require the number of minutes in a day.
i hour = 60 minutes
24 hours = 24 × 60 = 1440 minutes ( 24 hours in 1 day )
Then
fraction = [tex]\frac{48}{1440}[/tex] ( divide numerator/ denominator by 12 )
= [tex]\frac{4}{120}[/tex] ( divide numerator/ denominator by 4 )
= [tex]\frac{1}{30}[/tex]
If Jan can weed the garden in 2 hours and her husband can weed it in 1 hour and 30 minutes, find how long it takes them to weed the garden together.
Answer:
3 hours 30 minutes
Step-by-step explanation:
Jan :2 hours
her husband : 1 hour 30 minutes
2hr + 1 ½ hrs = 3 ½ hrs...that is 3 hours 30 minutes....?
Find COS Instructions: Find the value of the trigonometric ratio. Make sure to simplify the If needed
Answer:
Sin X = 12 / 37
Step-by-step explanation:
Given a right angled triangle, we are to obtain the Sin of the angle X ;
Using trigonometry, the sine of the angle X , Sin A is defined as the ratio of the angle opposite X to the hypotenus of the right angle triangle.
In the right angle triangle :
Sin X = opposite / hypotenus
Opposite = 12 ; hypotenus = 37
Sin X = 12 / 37
Can someone please help me solve the equation?
Answer:
B opition is right
Step-by-step explanation:
The domina a function of
GIVEN THAT GENERAL TERM =7n+4
evaluate sum of 5th termand 6th term
Answer:
general term - 7n+4
5th term - 7(5) + 4 = 39
6th term - 7(6) + 4 = 46
1. A tank is 3/5 full of water. After 330 litres of water is drawn out, it becomes 2/7 full. Find the capacity of the tank in litres.
Answer:
1050
Step-by-step explanation:
Let x = full capacity
[tex]\frac{3}{5} x=\frac{2}{7} x+330[/tex]
Move the variable to the left side by subtracting both sides by [tex]\frac{2}{7} x[/tex]
[tex]\frac{3}{5} x-\frac{2}{7}x=\frac{2}{7} x+330 -\frac{2}{7}x[/tex]
[tex]\frac{3}{5} x-\frac{2}{7} x=330[/tex]
Combine the like terms (don't forget about common denominator)
[tex]\frac{21}{35} x-\frac{10}{35} x=330[/tex]
[tex]\frac{11}{35} x=330[/tex]
Multiply both sides by [tex]\frac{35}{11}[/tex] to isolate the x
[tex](\frac{35}{11})\frac{11}{35} x=330(\frac{35}{11})[/tex]
[tex]x = 1050[/tex]
Find the equation of the line passing through the point (1, -5)
and perpendicular to y 1x + 2
Answer:
-8 and 3
Step-by-step explanation:
The slope of the line will be - 8, the equation is y=-8x+3
Hi friends,
Please assist with my question below.
In a right angle triangle, an angle of 30 degrees has an adjacent side which measures 17 cm. what is the length of its hypotenuse?
Answer : 19.6cm
I hope this helps you! Have a good day!
Please find this answer!! :)
Answer:
Amanda's box is in this case, the bigger one. Then subtract the Amanda's by Mary's. The Larger box is 70cm^3 larger then the smaller box.
Step-by-step explanation:
Amanda's box: 13.5*10*10= 1350cm^3
Mary's box: 20*8*8= 1280cm^3
1350-1280=70
The larger box is 70cm^3 larger then the smaller box.
If you have any questions regarding my answer tell me in the comments, i will come answer them. Have a good day.
Write an inequality, in slope-intercept form, for the graph below. If necessary,
use *<=' for sor">=' for .
(0,4)
(2.0)
Answer:
y<=(-2x+4)
Step-by-step explanation:
The equation of line is y=-2x+4. For the region left of it, y<=(-2x+4)
0.3,1/5,1/2,0.706,7/8,57.1%
Place following in ascending order
Answer:
the answer is 0.31/ 5.1/8.57.1% /207067
Step-by-step explanation:
ascending order from the smallest to the largest
Express -6 as the sum of a negative integer and a whole number
ASAP PLSSSSSSSS TYYYYYY
Answer:
20% of students prefer to go to the aquarium
50% of teachers prefer to go to the aquarium
Step-by-step explanation:
1.
8 students prefer the aquarium out of 40 students.
Set up an equation:
Variable x = percentage of students
8/40 = x/100
Cross multiply:
8 × 100 = 40 × x
800 = 40x
20 = x
Divide:
20%
Check your work:
40 students × 20%
Convert percentage into decimal:
40 × 0.20
8
8 students prefered the aquarium so this is correct!
2.
5 teachers prefer the aquarium out of 10 teachers.
Set up an equation:
Variable x = percentage of teachers
5/10 = x/100
5 × 100 = 10 × x
500 = 10x
50 = x
50%
Check your work:
10 × 0.50
5
Correct!
Quan điểm quản lý của trường phái đưc trị
.・。.・゜✭・Srry but which language is this!?
A)15.8 inches
B) 17.8 inches
C)16.2 inches
D)14.8 inches
Answer:
B
Step-by-step explanation:
Use pythagorean theorem
4^2+5^2=AC^2, AC= 6.4
7^2+9^2=CB^2, CB=11.4
If I toss a fair coin five times and the outcomes are TTTTT, then the probability that tails appears on the next toss is
1) 0.5
2) greater than 0.5
3) 1
4) less than 0.5
5) 0
Answer:
1. 0.5
Step-by-step explanation:
The probability of flipping a coin and landing on heads or tails is 100%. So 3)1 would be incorrect. In probability, we learned that just because something was picked more than once, it does not lower the chances of the thing being picked again. So 5)0 would be incorrect. The chances of getting tails are 50% also 0.5 and the chances of getting heads are 50% also 0.5. So 1 is correct.
There is a 0.5 percent chance that the following coin will land on its side.
What is Probability?Probability refers to potential. A random event's occurrence is the subject of this area of mathematics. The range of the value is 0 to 1.
The sample space, which is typically represented using set notation, contains a list of all the potential ordered outcomes as elements. A sample space with all possible outcomes exists for a series of five fair coin tosses. The example of a fair coin toss is 2*2*2H,T.
{HHHHH,HHHHT,HHHTH,HHTHH,HTHHH........TTTTT} The likelihood that the next coin will land on its side is always equal to It doesn't matter if previous results were TTTTT, HHHHH, or TTHT. The probability that the next number will be a tails is therefore still 0.5 in each of these cases as well as all others.
To learn more about Probability refer to:
https://brainly.com/question/24756209
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