Answer:
At 5% significant level, there is sufficient evidence to suggest that last year's mean local monthly bill for cell phone users has decreased from the 2001 mean of $47.37
Step-by-step explanation:
The given data are presented as follows;
32.88, 31.09, 16.13, 104.2, 47.65, 116.96, 61.97, 43.74, 13.52, 15, 37, 30.09, 16.93, 44.67, 28.08, 64.08, 16.17, 28.04, 57.67, 14.62, 61.32, 35.64, 88.95, 50.48, 16.41, 16.56, 13.48, 27.10, 15.50, 19.95, 23.45, 46.24, 41.8, 49.35, 81.16, 28.80, 32.48, 28.95, 31.60, 35.6, 24.74, 44.82, 51.62, 42.04, 22.43, 46.54, 48.32, 24.53, 77.21, 15.12, 126.84
We note that there are 51 data points, however, the points, 15 and 37 are given without decimal place values and therefore, they are taken as one data point to make 50 data points.
The given sample size = 50
The mean mean of the given data, [tex]\overline x[/tex] ≈ 41.01
The standard deviation of the given data, s ≈ 26.59
The null hypothesis, h₀; μ = 47.37
The alternative hypothesis, hₐ; μ < 47.37
The significant level, α = 5%
Therefore, we have;
The test statistics is given as follows;
[tex]t=\dfrac{\bar{x}-\mu }{\dfrac{s}{\sqrt{n}}}[/tex]
Plugging in the values gives;
[tex]t=\dfrac{41.01-47.37}{\dfrac{26.59}{\sqrt{50}}} \approx -1.69131[/tex]
The critical-t at 5% at df = n - 1 = 51 - 9 = 49 degrees of freedom and significance level, α of 5% (0.05) from a calculator = -1.676551
Given that the test statistic is larger than the critical-t, we therefore reject the null hypothesis. There is enough statistical evidence to suggest that last years mean monthly bill for cell phone users has decreased from 2001 mean to $47.37.
A culture of bacteria has an initial population of 470 bacteria and doubles every 8 hours. Using the formula P_t = P_0\cdot 2^{\frac{t}{d}}P t =P 0 ⋅2 d t , where P_tP t is the population after t hours, P_0P 0 is the initial population, t is the time in hours and d is the doubling time, what is the population of bacteria in the culture after 7 hours, to the nearest whole number?
Answer:
Step-by-step explanation:
The population of bacteria in the culture after 7 hours is approximately 883.
What is an exponential function?Several real-world phenomena, including population expansion, radioactive decay, compound interest, and the spread of diseases, are modeled using exponential functions. In calculus, where they are used to define the exponential and logarithmic functions—essential ideas in calculus and other fields of mathematics—they also play a significant role.
Using the formula [tex]P_t = P_0 \times 2^{\frac{t}{d}}[/tex], where P_t is the population after t hours, P₀ is the initial population, t is the time in hours and d is the doubling time, we can find the population of bacteria in the culture after 7 hours as follows:
Since the initial population is 470, we have P₀ = 470.
The doubling time is 8 hours, so we have d = 8.
Substituting these values into the formula, we get:
[tex]P_7 = 470 \times 2^{\frac{7}{8}}[/tex]
P₇≈ 882.77
To know more about an exponential function follow
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How do I solve this problem below!
Answer:
$5.44
Step-by-step explanation:
$1.75 + $1.26 + $1.08 + $0.52 = $4.56
$10.00 - $4.56 = $5.44
Which is the best type of graph to show the kilograms of food consumed and kilograms of food wasted in the
school cafeteria each day?
A. stem and leaf plot
B. line graph
C. dot plot
D. double bar graph
Answer:
Double Bar Graph
Step-by-step explanation:
The area of a square is 54 cm. What
is the length of each side of the
square?
A. between 8cm and 9cm
B. between 5cm and 6cm
C. between 6cm and 7cm
D. between 7cm and 8 cm
Naomi has a bag that contains pineapple chews, cherry chews, and peach chews. She performs an experiment. Naomi randomly removes a chew from the bag, records the result, and returns the chew to the bag. Naomi performs the experiment 72 times. The results are shown below: A pineapple chew was selected 31 times. A cherry chew was selected 3 times. A peach chew was selected 38 times. Based on these results, express the probability that the next chew Naomi removes from the bag will be pineapple chew as a decimal to the nearest hundredth.
Answer:
0.43
Step-by-step explanation:
Answer:
0.43
Step-by-step explanation:
The experiment occurred 72 times , pineapple was selected 31 times
Probability the next chew will be pineapple:
31/72 = 0.430555
Round to the nearest hundredth: 0.43
) Find the area of the shape.
Answer:
1/2Bh
Step-by-step explanation:
u never said we had to answer
For each equality decide whether the solution is represented by X less than 2 .5 or X greater than 2.5 -4x+5>-5 -25>-5(x+2.5)
Answer:
[tex]x<2.5[/tex] and [tex]x > 2.5[/tex] are the solutions
Step-by-step explanation:
Given
[tex]-4x + 5 > -5[/tex]
[tex]-25 > -5(x + 2.5)[/tex]
Required
Determine if their solution is x < 2.5 or x > 2.5
[tex]-4x + 5 > -5[/tex]
Collect like terms
[tex]-4x>-5-5[/tex]
[tex]-4x>-10[/tex]
Divide by -4
[tex]x<\frac{-10}{-4}[/tex]
[tex]x<2.5[/tex]
[tex]-25 > -5(x + 2.5)[/tex]
Open bracket
[tex]-25 > -5x - 12.5[/tex]
Collect like terms
[tex]5x > 25- 12.5[/tex]
[tex]5x > 12.5[/tex]
Divide by 5
[tex]x > \frac{12.5}{5}[/tex]
[tex]x > 2.5[/tex]
Rachel had a loan for $4,000 loan for 4 years.
She paid a total of $608 in simple interest over the 4 years.
What was the annual interest rate for the loan?
9514 1404 393
Answer:
3.8%
Step-by-step explanation:
The interest on a simple-interest loan is ...
I = Prt
where P is the principal value, r is the annual rate, and t is the number of years.
Solving for r, we get ...
r = I/(Pt) = 608/(4000×4) = 0.038 = 3.8%
The annual interest rate for the loan was 3.8%.
Find the circumference of a circle with a diameter of 35 ft. Use 22/7 for π.
Answer:
110
Step-by-step explanation:
the equation for circumference of a circle is 2 multiplied by pie multiplied by radius. so you do 22/7 multiply that by two and then divide 35 by 2 and get 17.5 and multiply that by the pie times 2
There are 7 apples and 15 oranges in a fruit basket at the grocery store. What is the ratio of oranges to all fruit
Answer:
15:22
Step-by-step explanation:
15 oranges and 22 fruits in total
please help, i'll give brainliest. (don't send a link please)
Answer:
A
Step-by-step explanation:
y+5<8
Subtract 5 from each side
5+5-5 <8-5
y<3
Since there is no equals sign, there is an open circle at 3
y is less than so the line goes to the left
Choice A
A farmer sells 6.5 kilograms of apples and pears at the farmer's market.
3
4
of this weight is apples, and the rest is pears. How many kilograms of pears did she sell at the farmer's market?
Answer:
1.625 kg
Step-by-step explanation:
Timmy and Sarah head out to dinner and Garfinkels in Vaile. Timmy brings $40 with him. If buy two French Dips costing $10.95 a piece and two sodas costs $1.95 each, how much does Timmy have left if there is a 6% sales tax and they tip 20% on the food including the sales tax
Answer:
$3.80
Step-by-step explanation: :)
Pls help help help pls
Answer:
Its the bottom left one :)
Step-by-step explanation:
A bag contains 6 red and 10 black marbles. If you pick a marble, record its color, and return it to the bag 200 times, how many times can you expect to pick a black marble?
Answer:
12.5
Step-by-step explanation:
6+10= 16 200/16=12.5
What is the unit rate for the ratio 4/7: 8/21?
Answer:
The unit rate is 1.5
Step-by-step explanation:
Given
[tex]Ratio = 4/7 : 8/21[/tex]
Required
Determine the unit rate
To do this, we need to express the ratio as:
[tex]Ratio = m : 1[/tex]
Where m is the unit rate
[tex]Ratio = 4/7 : 8/21[/tex]
Express as fraction
[tex]Ratio = \frac{4/7 }{ 8/21}[/tex]
Solve
[tex]Ratio = \frac{4}{7} * \frac{21}{8}[/tex]
[tex]Ratio = 1.5[/tex]
Express as ratio
[tex]Ratio = 1.5 : 1[/tex]
Hence, the unit rate is 1.5
What is the surface area of the composite figure shown?
Answer:
531 m²
Step-by-step explanation:
9x9x5=405 (5 sides that are 9x9, including the bottom)
1/2x9x7x4=126 (4 triangles on top)
405+126=531
No BS and show all of your work please and you must use the 1% or 10% method which I don’t know what that is LOL
Answers:
38% of 15 = 5.7
29% of 75 = 21.75
4% of 220 = 8.8
No idea what the 1% or 10% method is either. But these answers would be better then to leave the questions blank.
What type of correlation is shown in the graph?
A. Positive
B. Negative
C. No Correlation
D. Linear
Answer:
This graph shows a negative correlation
Hope this helps!
The test results for 4 students are: 96, 83, 78, and 83. If one more student's test score of 87 is added, what would increase?
A
median
B
mean
C
mode
D
range
Answer:
b
Step-by-step explanation:
find the value of x
plssss help me
Answer:
x = 20
Step-by-step explanation:
The angles are supplementary so:
7x + x + 20 = 180
8x + 20 = 180
8x = 160
x = 20
Victor buys 4 sleeves of golf balls. He has coupons for $0.75 off the regular price of each sleeve. After using the coupons, the total cost of the golf balls is $11. What is the regular price of each sleeve of golf balls?
2/6 = 1/2 1/3
which one is the answer
Answer:
1/3
Step-by-step explanation:
2+2+2=6
There are three 3's
What is the value of x
[tex]x {}^{2} \times 5x = 625[/tex]
Answer:
x = 5
Step-by-step explanation:
x^2 * 5x = 5x^3
5x^3 = 625 Divide by 5
x^3 = 625/5
x^3 = 125 Take the cube root of 125
x = 5
look at pic 10 points
Answer:
120
Step-by-step explanation: 10 x 12 = 120 m. Hope this helps
Which statements are true about triangle ABC and its translated image, A'B'C'? Select two options
A red die and a blue die are rolled. You win or lose money depending on the sum of the values of the two dice. If the sum is 6 or 10, you win $4. If the sum is 5, 9, or 12, you win $1. If the sum is any other value (2, 3, 4, 7, 8, or 11), you lose $2. Let X be a random variable that corresponds to your net winnings in dollars. What is the expected value of X
Answer:
The expected value of X is $0.0833.
Step-by-step explanation:
A probability is the number of desired outcomes divided by the number of total outcomes.
For each dice, there are 6 possible outcomes(values from 1 to 6). So for 2 dices, there are [tex]6^2 = 36[/tex] desired outcomes.
Desired outcomes:
Sum 5: (1,4), (2,3), (3,2), (4,1).
Sum 6: (1,5),(2,4),(3,3),(4,2),(5,1)
Sum of 9: (3,6), (4,5), (5,4), (6,3)
Sum of 10: (4,6), (5,5), (6,4)
Sum of 12: (6,6)
Probabilities:
5 + 3 = 8 outcomes in which the sum is 6 or 10, that is, 8/36 probability of winning $4.
4 + 4 + 1 = 9 outcomes in which the 5, 9, or 12, that is, 9/36 probability of winning $1.
36 - (8 + 9) = 36 - 17 = 19 remaining outcomes, that is, 19/36 probability of losing $2.
What is the expected value of X?
Multiplication of each outcome by its probability. So
[tex]E(X) = \frac{8}{36}*4 + \frac{9}{36}*1 - \frac{19}{36}*2 = \frac{8*4 + 9*1 - 19*2}{36} = \frac{32 + 9 - 38}{36} = \frac{3}{36} = 0.0833[/tex]
The expected value of X is $0.0833.
Tiffany said that there is no correlation between being a girl and playing in an intramural basketball league. Do you agree or disagree with Tiffany? Explain.
A.
Disagree, because the frequency indicates that there is a negative correlation to being a girl and being in an intramural league.
B.
Agreed; there is no correlation.
C.
Agree, because the frequency indicates that there is a positive correlation to being a girl and being in an intramural league.
Answer:
b
Step-by-step explanation:
During a flu epidemic, 35% of the school's students have the flu. Of those with the flu, 90% have high
temperatures. However, high temperatures are possible for people who do not have the flu. It is estimated that
12% of those without the flu have high temperatures.
If a student has a high temperature, what is the probability that the student has the flu?
Answer: 0.8015
Step-by-step explanation:
Let F= event that a person has flu
H= event that person has a high temperature.
As per given,
P(F) =0.35
Then P(F')= 1- 0.35= 0.65 [Total probability= 1]
P(H | F) = 0.90
P(H|F') = 0.12
By Bayes theorem, we have
[tex]P(F|H)=\dfrac{P(F)\timesP(H|F)}{P(F)\timesP(H|F)+P(F')\timesP(H|F')}\\\\=\dfrac{0.35\times0.90}{0.35\times0.90+0.65\times0.12}\\\\=\dfrac{0.315}{0.315+0.078}\approx0.8015[/tex]
Required probability = 0.8015
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