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
lara31 [8.8K]
3 years ago
9

A study of 420,076 cell phone users found that 131 of them developed cancer of the brain or nervous system. Prior to this study

of cell phone use, the rate of such
cancer was found to be 0.0224% for those not using cellphones. Complete parts (a) and (b)

a. Use the sample data to construct a 95 i dence interval estimate of the percentage of cell phone users who develop cancer of the brain or nervous system

%

(Round to three decimal places as needed)
Mathematics
1 answer:
Keith_Richards [23]3 years ago
7 0

Answer:

a) 95% Confidence interval = (0.026%, 0.037%) to 3 d.p

b) The result of the 95% confidence interval does not agree with the previous rate of such cancer because the value 0.0224% does not lie within this confidence interval obtained.

Step-by-step explanation:

Confidence Interval for the population proportion is basically an interval of range of values where the true population proportion can be found with a certain level of confidence.

Mathematically,

Confidence Interval = (Sample proportion) ± (Margin of error)

Sample proportion = (131/420076) = 0.0003118483 = 0.0312%

Margin of Error is the width of the confidence interval about the mean.

It is given mathematically as,

Margin of Error = (Critical value) × (standard Error)

Critical value at 95% confidence interval for sample size of 420,076 is obtained from the z-tables because the sample size is large enough for the properties of the sample to approximate the population properties.

Critical value = 1.960 (from the z-tables)

Standard error = σₓ = √[p(1-p)/n]

n = sample size = 420,076

σₓ = √(0.0003118×0.999688/420076) = 0.0000272421 = 0.0000272

95% Confidence Interval = (Sample proportion) ± [(Critical value) × (standard Error)]

CI = 0.000312 ± (1.96 × 0.0000272)

CI = 0.000312 ± 0.0000534

95% CI = (0.0002586055, 0.0003653945)

95% Confidence interval = (0.000259, 0.000365)

95% Confidence interval = (0.0259%, 0.0365%) = (0.026%, 0.037%) to 3 d.p

b) The result of the 95% confidence interval does not agree with the previous rate of such cancer because the value 0.0224% does not lie within this confidence interval obtained.

Hope this Helps!!!

You might be interested in
Find the sample size necessary in order to be 95% confident when determining the true mean weight within 2 units (EC2). Assume t
bogdanovich [222]

Answer:

(c) 43.

Step-by-step explanation:

Given:

Margin of error (E) = 2

Sample variance (s^{2}) = 44

Confidence level = 95%

The z- value at 95% confidence level is 1.96.

The sample using the provided information can be calculated as:

n=(\frac{z(s)}{E})^{2} \\n=\frac{z^{2} s^{2} }{E^{2} } \\n=\frac{1.96^{2} (44) }{2^{2} }\\n= 42.52\\n=43

Hence, the correct option is (c) 43.

8 0
3 years ago
43 17 30 52 61 12 21 30 11 27 for mean,median,mode,and range
tester [92]
The mean is 30.4 the median is 28.5 the mode is 30 and the range is 50
7 0
3 years ago
Steven wants to keep track of how many miles he walks in a year. He expects to walk 5 miles per day, and he has
WINSTONCH [101]

Answer:

The fourth choice.

Step-by-step explanation:

Because since 90 miles is basically counted as your first day, you do the number of days, n, minus 1 and then multiply it by 5 to find the number of miles walked after the first day. Then you add it to 90.

6 0
3 years ago
A pet store was selling 4 lizards for $47.88. If they ended up selling 6 lizards, how much would they have earned?
fgiga [73]

Answer:

Step-by-step explanation:

Step one- Find out how much it costs for one Lizard In this case, for four lizards it costs $47.88. To find the price for one lizard you divide 47.88 by four

$47.88/4Lizards=$11.97 per lizard.

Step two- Now that we have the price for one lizard, your question asks you how much for 6 lizards. We need to find that cost. To do so you multiply $11.97 by 6 for the lizards.

Your answer is $71.82

Hope This Helped :)

4 0
2 years ago
Read 2 more answers
Si f(x)=4x+5 cual es el valor de f(_3)?​
OLga [1]

Answer: Debería ser 7

Step-by-step explanation:

4 0
2 years ago
Other questions:
  • The dotplot shows the heights of 25 students in Mrs. Navard’s statistics class.
    14·1 answer
  • Complete the sentence 0.7 is 10 times as much as
    9·1 answer
  • Pls help me i will give brainliest!!!!!!!!!!!!!
    8·1 answer
  • Helppppppppppppppppppppppppp
    5·2 answers
  • Y 2 + 5y Choose the constant term that completes the perfect square trinomial.
    5·1 answer
  • Which should equal 105° to prove that f // g?<br> a<br> b<br> С<br> d
    13·1 answer
  • The point-slope form of the equation of a line that passes through points (8, 4) and (0, 2) is y – 4 = y minus 4 equals StartFra
    7·2 answers
  • FREE 10 POINTS!!! PUT ANYTHING HERE!!!! Merry Christmas :)
    10·2 answers
  • Use a calculator to find the value of the acute angle 0, to the nearest degree. <br> Cos0=0.3667
    7·1 answer
  • Jaxon has only nickels and dimes in his
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!