1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
kramer
2 years ago
8

18. A set of data has a sample mean of 65.4 and a standard deviation of 1.2. If the sample size is 45, what is the 99% confidenc

e interval of this data?
A. 65.10 and 65.70
B. 65.33 and 65.47
C. 65.05 and 65.75
D. 64.94 and 65.86
Mathematics
1 answer:
Agata [3.3K]2 years ago
5 0

Given:

Sample mean = 65.4

Standard deviation = 1.2

Sample size = 45

Confidence level = 99%

To find:

The confidence interval.

Solution:

The formula for confidence interval is

CI=\overline{x}\pm z^*\dfrac{s}{\sqrt{n}}

where, \overline{x} is sample mean, z* is confidence value, s is standard deviation and n is sample size.

Confidence value or z-value at 99% = 2.58

Putting the given in the above formula, we get

CI=65.4\pm 2.58\times \dfrac{1.2}{\sqrt{45}}

CI=65.4\pm 0.46

CI=65.4-0.46\text{ and }CI=65.4+0.46

CI=64.94\text{ and }65.86

Therefore, the correct option is D.

You might be interested in
Calculate the limit values:
Nataliya [291]
A) This particular limit is of the indeterminate form,
\frac{ \infty }{ \infty }
if we plug in infinity directly, though it is not a number just to check.

If a limit is in this form, we apply L'Hopital's Rule.

's
Lim_{x \rightarrow \infty } \frac{ ln(x ^{2} + 1 ) }{x} = Lim_ {x \rightarrow \infty } \frac{( ln(x ^{2} + 1 ) ) '}{x ' }
So we take the derivatives and obtain,

Lim_ {x \rightarrow \infty } \frac{ ln(x ^{2} + 1 ) }{x} = Lim_{x \rightarrow \infty } \frac{ \frac{2x}{x^{2} + 1} }{1}

Still it is of the same indeterminate form, so we apply the rule again,

Lim_{x \rightarrow \infty } \frac{ ln(x ^{2} + 1 ) }{x} = Lim_{x \rightarrow \infty } \frac{ 2 }{2x}

This simplifies to,

Lim_{x \rightarrow \infty } \frac{ ln(x ^{2} + 1 ) }{x} = Lim_{x \rightarrow \infty } \frac{ 1 }{x} = 0

b) This limit is also of the indeterminate form,

\frac{0}{0}
we still apply the L'Hopital's Rule,

Lim_ {x \rightarrow0 }\frac{ tanx}{x} = Lim_ {x \rightarrow0 } \frac{ (tanx)'}{x ' }

Lim_ {x \rightarrow0 }\frac{ tanx}{x} = Lim_ {x \rightarrow0 } \frac{ \sec ^{2} (x) }{1 }

When we plug in zero now we obtain,

Lim_ {x \rightarrow0 }\frac{ tanx}{x} = Lim_ {x \rightarrow0 } \frac{ \sec ^{2} (0) }{1 } = \frac{1}{1} = 1
c) This also in the same indeterminate form

Lim_ {x \rightarrow0 }\frac{ {e}^{2x} - 1 - 2x}{ {x}^{2} } = Lim_ {x \rightarrow0 } \frac{ ({e}^{2x} - 1 - 2x)'}{( {x}^{2} ) ' }

Lim_ {x \rightarrow0 }\frac{ {e}^{2x} - 1 - 2x}{ {x}^{2} } = Lim_ {x \rightarrow0 } \frac{ (2{e}^{2x} - 2)}{ 2x }

It is still of that indeterminate form so we apply the rule again, to obtain;

Lim_ {x \rightarrow0 }\frac{ {e}^{2x} - 1 - 2x}{ {x}^{2} } = Lim_ {x \rightarrow0 } \frac{ (4{e}^{2x} )}{ 2 }

Now we have remove the discontinuity, we can evaluate the limit now, plugging in zero to obtain;

Lim_ {x \rightarrow0 }\frac{ {e}^{2x} - 1 - 2x}{ {x}^{2} } = \frac{ (4{e}^{2(0)} )}{ 2 }

This gives us;

Lim_ {x \rightarrow0 }\frac{ {e}^{2x} - 1 - 2x}{ {x}^{2} } =\frac{ (4(1) )}{ 2 }=2

d) Lim_ {x \rightarrow +\infty }\sqrt{x^2+2x}-x

For this kind of question we need to rationalize the radical function, to obtain;

Lim_ {x \rightarrow +\infty }\frac{2x}{\sqrt{x^2+2x}+x}

We now divide both the numerator and denominator by x, to obtain,

Lim_ {x \rightarrow +\infty }\frac{2}{\sqrt{1+\frac{2}{x}}+1}

This simplifies to,

=\frac{2}{\sqrt{1+0}+1}=1
5 0
3 years ago
Which is the solution to the inaquality y+15<3
jek_recluse [69]

Answer:

y < - 12

Step-by-step explanation:

Given

y + 15 < 3 ( subtract 15 from both sides )

y < - 12

5 0
3 years ago
What is the missing angle?
AleksAgata [21]

Answer:

318

Step-by-step explanation:

151+116+135+136+164+101+139=942

1260-942=318

7 0
3 years ago
Read 2 more answers
PLS HELP ME ASAP!! TEN POINTS!!! Select each correct answer.
FinnZ [79.3K]

Answer:

It's 3

Step-by-step explanation:

if you go to desmos graphing calculator it'll help you get the solutions for these if you type it in every number and letter and for exponents type ^ its shift then type 6.

8 0
1 year ago
2. How much heat is needed to warm .052 kg of gold from 30°C to 120°C
Doss [256]

Answer: 90 degrees Celsius

Step-by-step explanation:

120-30 = 90

7 0
3 years ago
Other questions:
  • What is 1,986x566 so I can do my homework
    14·2 answers
  • A=2 b=2 c=1 Find the value of 2abcosC
    8·1 answer
  • Given: △MOP, Perimeter of △MOP=12+4 sqr rt. 3 m∠P=90°, m∠M=60° Find: MP
    7·2 answers
  • Ax+By=C (I need to solve for x)
    12·1 answer
  • What improper fraction can be written as a whole number. 10/6 12\6 14\6 16\6?
    12·1 answer
  • HELP ME PLEASE !
    13·1 answer
  • At noon, ship A is 180 km west of ship B. Ship A is sailing east at 40 km/h and ship B is sailing north at 35 km/h. How fast is
    6·1 answer
  • On a scale drawing, the length of a swimming pool is 40 cm. The actual length of the swimming pool is 18 m.
    11·1 answer
  • Find the equation of the line that contains The given point and is perpendicular to the given line. Write the equation in slope
    5·1 answer
  • Help asap
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!