A researcher reported that 71.8% of all email sent in a recent month was spam. A system large corporation believes that the percentage at his company may be 77 % . He manager at a examines a random sample of 500 emails received at an email server, and finds that 361 of the messages are spam.

Required:
Can you conclude that less than 77% of emails are spam?

Answers

Answer 1

Answer:

p-value = 0.0054

at 0.05 level  of significance ∝

p-value ( 0.0054 ) is less than significance level ∝ ( 0.05 )

Thus we Reject Null hypothesis  H₀

Hence, there is enough evidence to conclude that less than 77% of emails are spam.

Step-by-step explanation:

Given the data in the question;

Sample size n = 500

x = 361

p₀ = 77% = 0.77

q₀ = 1 - p₀ = 1 - 0.77 = 0.23

p = x / n = 361 / 500 = 0.722

Hypothesis;

Null hypothesis             H₀ : p ≥  77% or 0.77

Alternative hypothesis Hₐ : p ≥  77% or 0.77

Test Statistic

z = ( p - p₀ ) / √( ( p₀ × q₀ ) / n )  

so we substitute

z = ( 0.722 - 0.77 ) / √( ( 0.77 × 0.23 ) / 500 )  

z = -0.048 / √( 0.1771 / 500 )  

z = -0.048 / √0.0003542  

z = -0.048 / 0.01882

z = -2.55

so our p-value will be;

p-value = p( z < -2.55 ) {from table }

p-value = 0.0054

at 0.05 level  of significance ∝

p-value ( 0.0054 ) is less than significance level ∝ ( 0.05 )

Thus we Reject Null hypothesis  H₀

Hence, there is enough evidence to conclude that less than 77% of emails are spam.


Related Questions

A clock lost 2 minutes and 36 seconds in 78 days. How many seconds did it lose per day?

Answers

the clock lost 2 seconds per day

Find the volume of the prism below if each cube has a side length of 1/8 of a foot

Answers

Answer:

[tex]Volume = \frac{3}{128}ft^3[/tex]

Step-by-step explanation:

Given

[tex]Length = 1\ cube[/tex]

[tex]Width = 3\ cubes[/tex]

[tex]Height = 4\ cubes[/tex]

[tex]1\ cube = \frac{1}{8}ft[/tex]

Required

The volume of the cube

Start by calculating the dimension in ft

[tex]Length = 1\ cube[/tex]

[tex]Length = 1 * \frac{1}{8}ft[/tex]

[tex]Length = \frac{1}{8}ft[/tex]

[tex]Width = 3\ cubes[/tex]

[tex]Width = 3 * \frac{1}{8}ft[/tex]

[tex]Width = \frac{3}{8}ft[/tex]

[tex]Height = 4\ cubes[/tex]

[tex]Height = 4 * \frac{1}{8}ft[/tex]

[tex]Height = \frac{1}{2}ft[/tex]

So, the volume is:

[tex]Volume = Length * Width * Height[/tex]

[tex]Volume = \frac{1}{8}ft * \frac{3}{8}ft * \frac{1}{2}ft[/tex]

[tex]Volume = \frac{1}{8} * \frac{3}{8} * \frac{1}{2}ft^3[/tex]

Using a calculator, we have:

[tex]Volume = \frac{3}{128}ft^3[/tex]

Determine the area of this triangle...

Answers

Answer:

650,000 cm²

Step-by-step explanation:

10x6.5=65 METERS squared.  They want it in CENTIMETERS squared.

65m² = 650,000cm²

Answer:

32.5[tex]m^{2}[/tex]

Step-by-step explanation:

The coloured triangle with the blank triangle area =

(14m x 6.5m)÷2 = 45.5[tex]m^{2}[/tex]

The blank triangle area =

[(14-10m) x 6.5m]÷2 = 13[tex]m^{2}[/tex]

Therefore:

The coloured triangle area =

(45.5 - 13)[tex]m^{2}[/tex]

=32.5[tex]m^{2}[/tex]

You are going to use an incline plane to lift a heavy object to the too of shelving unit with a height of 7 ft. The base if the incline plane is 26 ft from the shelving unit. What is the length of the incline plane? FAST HELPPP MEE PLEASEE IM STUCK

Answers

Answer:

17.46 ft

Step-by-step explanation:

The inclined plane is in the shape of a right triangle, therefore we can use the Pythagorean theorem to find the length of the inclined plane. The formula for this theorem is the following

[tex]a^{2} + b^{2} = c^{2}[/tex]

Where a and b are the two sides and c is the hypotenuse/inclined side. Therefore, we can simply plug in the lengths of the two sides into the formula and solve for c.

[tex]a^{2} + b^{2} = c^{2}[/tex]

[tex]7^{2} + 16^{2} = c^{2}[/tex]

[tex]49 + 256 = c^{2}[/tex]

[tex]305 = c^{2}[/tex]   ... square root both sides

17.46 = c

pls pls help i realy need help

Answers

Answer:

a <= 3

Step-by-step explanation:

Please this a really easy question. Does this mean I got an A on this test?! Please answer!!!!!!!!!!!!!!!

Answers

Answer:

yes it does. good job on your A.

Step-by-step explanation:

Answer:

Yes

Step-by-step explanation:

Question 12: Angle M and Angle P are what type of angles?
m
n
o
Р
qr
st
adjacent
right
obtuse
O vertical

Answers

Answer:

adjacent anf o vertical

Step-by-step explanation:

х
The table of values below represent an exponential function. Write an exponential equation that models the data.
у
-2 23
-1 16.1
0 11.27
1 7.889
2 5.5223
a.
y = 23(0.7)
y = 16.1(1.7)
C. y = 11.27(0.7)
d.
y = 11.27(1.3)
b.

Answers

9514 1404 393

Answer:

  C.  y = 11.27(0.7^x)

Step-by-step explanation:

The table value (x, y) = (0, 11.27) tells you the multiplier of the exponential term will be 11.27. The decreasing values tell you the base of the exponential term is less than 1. Only answer choice C matches these requirements.

The "freshman 15" is the name of a common belief that college students, particularly women, gain an average of 15 pounds during their first year of college. In one study of 110 female first‐year college students (Psychology of Women Quarterly, vol 17, pp.119‐126, 1993), the mean weight was 130.6 pounds at the beginning of the study and 131.4 pounds six months later. The standard deviation was about 20 pounds at each time.

Required:
a. Estimate the change in the mean weight over this six‐month period.
b. Is this sufficient information to find a confidence interval or conduct at estimate about the change in the mean over six months? If not what else do you need to know?

Answers

Answer:

A) - 0.8 Ibs

B) There isn't enough information

    The standard deviations of the difference scores is needed

Step-by-step explanation:

N = 110 female first year college students

Mean weight at beginning of study = 130.6 Ib

Mean weight after six ( 6 ) months = 131.4 Ib

standard deviation = 20 pounds

A) Determine the change in the mean weight over the six(6) months period

mean weight at beginning - mean weight after six(6) months

= 130.6 - 131.4

= -0.8 Ibs

B) Determine if there is sufficient information to find a confidence interval

There isn't sufficient information to determine the confidence interval but in other to determine the confidence interval or conduct an estimate You need standard deviations of the difference scores to calculate the standard error of mean

Helllppppp me quick!!!!!!!

Answers

Answer:

F(x) =2x+3

Step-by-step explanation:

F(x) =2x+3...............

Answer:

[tex]consider : (0, 3) \: and \: (1, 5) \\ gradient = \frac{5 - 3}{1 - 0} \\ = 2 \\ from : \: y = mx + c \\ consider \: (0, 3) \\ 3 = (2 \times 0) + c \\ c = 3 \\ therefore \: equation \: is : \\ y = 2x + 3[/tex]

ILL MARK BRAINLIEST!
Which of these points lies on the graph of the equation x – 9 = y?
A. (3, 6)
B. (2, 11)
C. (-3,-6)
D. (-2, -11)

Answers

Answer:

D. (-2, -11)

Step-by-step explanation:

Since -2 - 9 = -11, it fits into the equation x - 9 = y, with -2 being "x" and -11 being "y".

And out of all the options, D is the only one that works.

A watermelon that weighed 12 pounds cost $5.76. What was the cost per ounce of the watermelon?

Answers

Answer:

69.12

Step-by-step explanation:

12x5.76

Answer

69

Step-by-step explanation:

12×5.75=69

A leasing firm claims that the mean number of miles driven annually, , in its leased cars is less than miles. A random sample of cars leased from this firm had a mean of annual miles driven. It is known that the population standard deviation of the number of miles driven in cars from this firm is miles. Assume that the population is normally distributed.
Is there support for the firm's claim at the level of significance?
Perform a one-tailed test.
null hypothesis?
alternative hypothesis?
type of test statistic?
value of the test statistic?
the p-value?
Can we support the leasing firm's claim that the mean number of miles driven annually is less than 12800 miles?

Answers

Complete question is;

A leasing firm claims that the mean number of miles driven annually, u , in its leased cars is less than 12800 miles. A random sample of 50 cars leased from this firm had a mean of 12499 annual miles driven. It is known that the population standard deviation of the number of miles driven in cars from this firm is 3140 miles. Is there support for the firm's claim at the 0.05 level of significance?

Perform a one-tailed test.

null hypothesis?

alternative hypothesis?

type of test statistic?

value of the test statistic?

the p-value?

Can we support the leasing firm’s claim that the mean number of miles driven annually is less than 12800 miles?

Answer:

A) Null hypothesis; μ ≥ 12800

Alternative hypothesis; μ < 12800

B) type of test statistic: z-score test

C) test statistic; z = -0.678

D) p - value = 0.2489

E) No, we can't support the leasing firms claim

Step-by-step explanation:

We are given;

Population mean; μ = 12800 miles

Sample mean; x¯ = 12499 miles

Sample size; n = 50

Population standard deviation; σ = 3140

Let's define the hypothesis;

Null hypothesis; μ ≥ 12800

Alternative hypothesis; μ < 12800

The alternative hypothesis is the claim.

Since sample size is greater than 30, we will use z-score test.

Formula for z-score;

z = (x¯ - μ)/(σ/√n)

z = (12499 - 12800)/(3140/√50)

z = -0.678

From online p-value from z-score calculator attached, using z = -0.678 with one tailed hypothesis and significance value of 0.05,we have;

p - value = P(z < -0.678) = 0.2489

The p-value is greater than the significance value, so we will fail to reject the null hypothesis and conclude that there is no sufficient information to support the leasing firm's claim

Can someone help me I am stuck on this question it would mean the world if u helped me! and TYSM! for the people who helped me have a wonder full day!

Answers

Answer:

1.25 gallons of orange juice needed

Step-by-step explanation:

2(3/4)=3/2 cups per 1 person

24 x 3/2=36 cups for everyone

36 cups=18 pints

18-8=10 pints of orange juice

10 pints = 1.25 gallon

Answer:

1.25 gallons of orange juice

Step-by-step explanation:

24x2=48

3/4x48=36

36 cups into pints is 18 pints

18-8=10

10 pints into gallons is 1.25 gallons

Which one of the following is an ordered pair?


{-3, 5}


(2, 4, 0)


(0, 6)


1, 3

Answers

9514 1404 393

Answer:

  (c)  (0, 6)

Step-by-step explanation:

Conventionally, an "ordered pair" is a pair of items in parentheses, separated by a comma. The items don't have to be numbers. (0, 6) is an ordered pair.

__

Comments on the other answer choices

Curly braces are usually used as delimiters of a set, not an ordered pair.

Three items do not constitute a "pair." Rather, they are a "triple."

Items without any particular indicator of grouping are usually not considered a "pair."

Plz help its my last grade and i really need it to be good

Answers

Answer:

Option D

Step-by-step explanation:

[tex]60+45+75=180[/tex]

[tex]Triangle ~has ~the~ sum ~of ~angle =180[/tex]

--------------------------

hope it helps...

have a great day!!

Answer:

D will be your answer!!

Step-by-step explanation:

hope it helps

which system of equations does this graph represent?
1) y=x^2-5
y=-x+1

2) y=x^2-5

y=-x-1

3) y=x^2+5
y=-x+1

4) y=x^2+5
y=-x-1

Answers

Answer:

1

Step-by-step explanation:

First, we can find the equation of the parabola. The standard form of a parabola is ax^2 + bx + c,

where c is the y-intercept. The y-intercept on the graph is -5, and every option starts with x^2, so the equation must be x^2 - 5. This rules out options 3 and 4.

Next, we can find the equation of the line. The options are all given in slope-intercept form: y = mx + b, where b is the y-intercept. The y-intercept on the graph is 1, and option 1 has 1 in the place of b. Therefore, option 1 is the answer.

Classify the following triangle. Check all that apply.
A
I A. Equilateral
B. Right
C. Acute
I D. Isosceles
O E Obtuse
O F. Scalene

Answers

Answer:

A and C

Step-by-step explanation:

The triangle given has three equal sides and three equal angles.

Since the sum of a triangle = 180°, therefore, each angle equals 60°

Thus, we can conclude that the triangle is an acute triangle because an acute triangle has all three sides measuring less than 90°. This implies that all it's angles are acute angles.

Also, since all its sides are equal and the same as well as it's three angles, based on this, we can equally say the triangle is an equilateral triangle.

The triangle can be referred to as an acute triangle and also as an equilateral triangle.

Raw scores on a certain standardized test one year were normally distributed, with a mean of 156 and a standard deviation of 23. If

48,592 students took the test, about how many of the students scored less than 96?

Answers

Answer:

About 220 of the students scored less than 96

Step-by-step explanation:

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.

Mean of 156 and a standard deviation of 23.

This means that [tex]\mu = 156, \sigma = 23[/tex]

Proportion that scored less than 96:

p-value of Z when X = 96. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{96 - 156}{23}[/tex]

[tex]Z = -2.61[/tex]

[tex]Z = -2.61[/tex] has a p-value of 0.00453.

About how many of the students scored less than 96?

0.00453 out of 48592.

0.00453*48592 = 220.1.

Rounding to the closest integer:

About 220 of the students scored less than 96

Answer:

220

Step-by-step explanation:

#platolivesmatter

A force of 350 pounds is resolved into component forces. If it makes an angle of 67° with the horizontal, find the larger component. 322 lb 235 lb 137 lb 380 lb

Answers

Answer: [tex]322\ lb[/tex]

Step-by-step explanation:

Given

The magnitude of the force [tex]F=350\ \text{Pounds}[/tex]

The force makes an angle of [tex]67^{\circ}[/tex] with the horizontal

So, the components of the force are

[tex]\Rightarrow F\cos 67^{\circ}, F\sin 67^{\circ}\\\Rightarrow F\cos 67^{\circ}=350\cos 67^{\circ}\\\quad \quad =136.75\ lb\\\text{Similarly, }\\\Rightarrow F\sin 67^{\circ}=350\sin 67^{\circ}\\=322.17\ lb[/tex]

The larger among the two is [tex]F\sin 67^{\circ}[/tex] i.e. [tex]322\ lb[/tex]

Find the side lengths of the triangle in this picture.​

Answers

Answer:

Hypotenuse: 41 meters, Long leg: 40 meters, Short leg: 9 meters.

Step-by-step explanation:

According to the statement, we have the following information about the lengths of the right triangle:

Hypotenuse

[tex]3\cdot x + 14[/tex]

Long leg

[tex]3\cdot x + 13[/tex]

Short leg

[tex]x[/tex]

By the Pythagoric Theorem, we have the following expression:

[tex](3\cdot x + 14)^{2} = x^{2} + (3\cdot x + 13)^{2}[/tex] (1)

[tex]9\cdot x^{2}+84\cdot x + 196 = x^{2} + 9\cdot x^{2} + 78\cdot x + 169[/tex]

[tex]9\cdot x^{2} + 84\cdot x + 196 = 10\cdot x^{2} + 78\cdot x +169[/tex]

[tex]x^{2} -6\cdot x -27 = 0[/tex]

[tex](x-9)\cdot (x+3) = 0[/tex]

As length is a positive variable by nature, then the only possible solution is [tex]x = 9[/tex]. Lastly, the side lengths of the right triangle are:

Hypotenuse: 41 meters, Long leg: 40 meters, Short leg: 9 meters.

PLEASE ANSWER ASAP WILL MARK BRAINLIEST!!

Select the favorable outcomes for rolling a sum of seven.

O (5-1) (5-2) (5-3) (5-4) (5-5) (5-6)
O (1-6) (2-5) (3-4) (4-3) (5-2) (6-1)
O (1-1) (1-2) (1-3) (2-1) (2-2)(3-1)
O (1-1) (2-2) (3-3) (4-4) (5-5) (6-6)

Answers

Answer:

The second one

O (1-6) (2-5) (3-4) (4-3) (5-2) (6-1)

Step-by-step explanation:

Favorable outcome is the outcome that we are looking for

The outcome that we are looking for when rolling two = die is a sum of 7

The set (1-6) (2-5) (3-4) (4-3) (5-2) (6-1) all add up to equal 7

( 1 , 6 ) 1 + 6 = 7

( 2 , 5 ) 2 + 5 = 7

( 3 , 4 ) 3 + 4 = 7

etc.

Which means that they are the favorable outcomes for rolling a seven

Daryl can jump 2 1/2 yards. sarah can jump 8 feet michell can jump 72 inches, witch statement is true.

Answers

Answer:

Where are the statements?

Step-by-step explanation:

Where are the statements?

I can’t seem to find the value of n in this peoblem

Answers

Answer:

9

Step-by-step explanation:

you can always use guess-and-check:

124 seems rather high

(6)P(2) = 6!/4! = 6x5 ≠ 72

(9)P(2) = 9!/7! = 9x8 = 72

Answer:

i think the value of n is 12

An equation with real coefficients has (1-i), 3, and 4 among its roots. What is the lowest possible degree of the equation?
A: 3
B: 4
C: 5
D: 6

Answers

Answer:

D

Step-by-step explanation:

A store sells small notebooks for ​$8 and large notebooks for ​$16. If a student buys 6 notebooks and spends ​$80​, how many of each size did he​ buy?

Answers

Answer:

Small-6

Large-2

Step-by-step explanation:

small-$8

large-$16

$8×6=$48

$80-$48=$32

32÷16=2(large)

find the common difference of the arithmetic sequence 3, -2, -7

Answers

Answer:

-5

Step-by-step explanation:

To find the common difference, take the second term and subtract the first term

-2 - 3 = -5

Check with the third term and the second term

-7 - (-2) = -7 +2 = -5

The common difference is -5

Find the length of a to the nearest tenth using the Pythagorean theorem

Answers

Answer:

Ab^2 = CA^2 + BC^2

8^2 = 6^2 + a^2

64 = 36 + a^2

64-36 = a^2

28 = a^2

square root of 28 = square root of a^2

5 ,29 = a

5 = a

X/4 < 1.5 show steps please

Answers

Step-by-step explanation:

x/4<1.5x<1.5×4x<6

stay safe healthy and happy...

Please help I really need help. I am super confused and would really appreciate it

Answers

Answer:

[tex] a^{5} [/tex]

Step-by-step explanation:

Given the mathematical expression;

a⁸/a³

To rewrite the expression in the form [tex] a^{m} [/tex]

We would have to apply the law of indices.

[tex] Law \; of \; division = \frac {a^{x}}{a^{y}} = a^{x - y} [/tex]

[tex] Law \; of \; division = \frac {a^{8}}{a^{3}} = a^{8 - 3} [/tex]

[tex] a^{m} = a^{8 - 3} = a^{5} [/tex]

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