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
oksian1 [2.3K]
3 years ago
6

In the past decades there have been intensive antismoking campaigns sponsored by both federal and private agencies. In one study

of national smoking trends, two random samples of U.S. adults were selected in different years: The first sample, taken in 1995, involved 4276 adults, of which 1642 were smokers. The second sample, taken in 2010, involved 3908 adults, of which 1415 were smokers. The samples are to be compared to determine whether the proportion of U.S. adults that smoke declined during the 15-year period between the samples.Let p1 be the proportion of all U.S. adults that smoked in 1995. Let p2 denote the proportion of all U.S. adults that smoked in 2010.The value of the z statistic for testing equality of the proportion of smokers in 1995 and 2010 isA. z = 1.39.B. z = 1.66.C. z = 2.05.D. z = 4.23.
Mathematics
1 answer:
astra-53 [7]3 years ago
4 0

Answer:

C. z = 2.05

Step-by-step explanation:

We have to calculate the test statistic for a test for the diference between proportions.

The sample 1 (year 1995), of size n1=4276 has a proportion of p1=0.384.

p_1=X_1/n_1=1642/4276=0.384

The sample 2 (year 2010), of size n2=3908 has a proportion of p2=0.3621.

p_2=X_2/n_2=1415/3908=0.3621

The difference between proportions is (p1-p2)=0.0219.

p_d=p_1-p_2=0.384-0.3621=0.0219

The pooled proportion, needed to calculate the standard error, is:

p=\dfrac{X_1+X_2}{n_1+n_2}=\dfrac{1642+1415}{4276+3908}=\dfrac{3057}{8184}=0.3735

The estimated standard error of the difference between means is computed using the formula:

s_{p1-p2}=\sqrt{\dfrac{p(1-p)}{n_1}+\dfrac{p(1-p)}{n_2}}=\sqrt{\dfrac{0.3735*0.6265}{4276}+\dfrac{0.3735*0.6265}{3908}}\\\\\\s_{p1-p2}=\sqrt{0.00005+0.00006}=\sqrt{0.00011}=0.0107

Then, we can calculate the z-statistic as:

z=\dfrac{p_d-(\pi_1-\pi_2)}{s_{p1-p2}}=\dfrac{0.0219-0}{0.0107}=\dfrac{0.0219}{0.0107}=2.05

z=2.05

You might be interested in
Does anyone know any good Algebra 1 studying tips. Big tests coming up.
serious [3.7K]

Answer:

Review your notes, make flashcards, go back to your textbook and solve problems you haven't solved. Just keep doing practice problems

4 0
3 years ago
The number 900 has an interesting property in that the only primes that divide into it evenly are 2, 3, and 5. What are the next
Tasya [4]

900 = 2 · 2 · 3 · 3 · 5 · 5

Next numbers:

2 · 2 · 2 · 3 · 3 · 3 · 5 · 5 · 5 = 900 · 15 = 13,500

2 · 2 · 2 · 2 · 3 · 3 · 3 · 3 · 5 · 5 · 5 · 5 = 13,500 · 15 = 202,500

202,500 · 15 = 3,037,500

3,037,500 · 15 = 45,562,500

....

3 0
3 years ago
86-[(4-9)².3] simplify
Sonja [21]

Answer: 218

Step-by-step explanation:

4 0
2 years ago
Read 2 more answers
Which of the slopes below represents a line that is perpendicular to the line =13+4 ?
dedylja [7]

Answer:

c

Step-by-step explanation:

7 0
3 years ago
6.1 is 90% of what number
n200080 [17]

Step-by-step explanation:

let the unknown number be x

90/100 × x =6.1

× = 6.1 × 100/ 90

x = 610/ 90

x = 6.778

8 0
3 years ago
Other questions:
  • Thanks for your help
    11·1 answer
  • A mathematics professor lost a test paper belonging to one of her students. she remembered that the mean score for the class of
    10·1 answer
  • Stone bridge neighborhood garage sale had these cash receipts for 5 days: $214.50, $125.17, $245.30, $165.34, $58.75. What were
    5·2 answers
  • What is the geometric mean for 6 and 18.
    14·2 answers
  • Mae Ling earns a weekly salary of $375 plus a 7.0% commission on sales at a gift shop. How much would she make in a work week if
    10·1 answer
  • What fraction do you get when you divide 5 by 6?
    9·1 answer
  • What is the slope of the line?
    15·2 answers
  • What is the factored form of this expression?
    7·1 answer
  • Drag the tiles to the boxes to form correct pairs. Not all tiles will be used.
    9·2 answers
  • Express your answer in form a+bi (14+60i)+(-30+2i)
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!