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
il63 [147K]
3 years ago
9

A philanthropic organization helped a town in Africa dig several wells to gain access to clean water. Before the wells were in p

lace, an average of 120 infants contracted typhoid each month. After the wells were installed, the philanthropic organization surveyed for nine months and found an average of 90 infants contracted typhoid per month. Assume that the population standard deviation is 40 and the number of infants that contract typhoid is normally distributed. Specify the null and alternative hypotheses to determine whether the average number of infants that contract typhoid has decreased because the wells were put in place.
Mathematics
1 answer:
Bond [772]3 years ago
5 0

Answer:

H0 : μ = 120

H1 : μ < 120

We Can conclude that the number of infants that contract typhoid has reduced because the wells were put in place.

Step-by-step explanation:

Average Number of infants who contracted typhoid monthly = 120

Average Number of infants who contracted typhoid monthly after well installation = 90

The null and alternative hypothesis :

H0 : μ = 120

H1 : μ < 120

Obtain the test statistic :

(Xbar - μ) ÷ s/sqrt(n)

(90 - 120) ÷ 40/sqrt(9)

-30 ÷ 13.3333

= - 2.25

The Pvalue at 95% confidence, df = n-1 = 9 - 1 = 8

Tcritical at 95%, df = 8 ; one tailed = 0.02728

Decision region :

Pvalue < α ; Reject H0

0.02728 < 0.05 ; Hence, we conclude that there is significant evidence that the average number of infants that contract typhoid has decreased because the wells were put in place.

You might be interested in
I don’t understand this someone pls help
omeli [17]

To solve this, you need to plug in the numbers for <em>h</em>.

-4(-12) ≥ 8       48 ≥ 8  yes

-4(-7) ≥ 8         28 ≥ 8  yes

-4(-5) ≥ 8        20 ≥ 8  yes

-4(-3) ≥ 8        12 ≥ 8  yes

-4(-2) ≥ 8         8 ≥ 8  yes

-4(-1) ≥ 8         4 ≥ 8  no

-4(1) ≥ 8          -4 ≥ 8  no

-4(3) ≥ 8         -12 ≥ 8 no

-4(8) ≥ 8         -32 ≥ 8  no

Hope this helped!

7 0
3 years ago
What is the area of the garden?
xenn [34]

Answer:

42 square meters

Step-by-step explanation:

rectangle: 3 x 6= 18 square meters

square: 4 x 5= 20 square meters

triangle: 4 x 2 x 1/2= 4 square meters

18 + 20 + 4= 42 square meters

8 0
3 years ago
Read 2 more answers
Find cos q if q is an angle in standard position and the point with coordinates (3, –4) lies on the terminal side of the angle.
gayaneshka [121]

Answer:

cos q = 3/5

Step-by-step explanation:

Standard position means the vertex (point or corner of the angle) is at (0,0) and one side of the angle is glued to the positive x-axis (facts, but not technical math terms) See image. Special triangles have all three sides nice and clean with whole number lengths, we call these Pythagorean triples. 3-4-5 is your most basic Pythagorean triple. So we don't even have to calculate the hypotenuse, see image. Now the triangle shown is easy to work with, using entry-level trig...cos = ADJ/HYP. So we get 3/5=.6 BUUuuuut, the angle q in the original problem is actually the giant angle, marked in yellow (see image) and we're in the fourth quadrant which means there's negative numbers all over the place. So just to be sure the answer is .6 and not -.6 Check your signs. One trick to remember is the ASTC markings in the quadrants. I use All Students Take Calculus, but what it means is in the first quadrant All the trig functions are positive. Only Sine (and fam) are positive in the 2nd quadrant. Tan (and fam) in the 3rd and Cos and fam in the 4th quadrant. It's a good quick check.

cos q = 3/5 OR cos q = .6

8 0
2 years ago
What is the value of of angle BAD:<br><br> 30◦<br> 5◦<br> 15◦<br> 20◦
Kitty [74]
From 2x+5=3x, then x=5.
5 0
3 years ago
What is the measure of the exterior angle at D?
coldgirl [10]

Answer:

360-63

=297 my guy

7 0
3 years ago
Other questions:
  • Pretend you are coaching a sports team—you pick the sport. What are some ways you would use matrices on the job?
    5·1 answer
  • A Web music store offers two versions of a popular song. The size of the standard version is 2.5 megabytes (MB). The size of the
    13·1 answer
  • Two stores carry a similar stereo for the same original price of $573. One store offers a 16% discount and the second store sell
    8·2 answers
  • Solve the following inequation and represent the solution set on the number line
    15·1 answer
  • Which fraction has a value that's equal to 3∕4?
    6·2 answers
  • Please help - and explain
    14·1 answer
  • What is the best way to remember trigonometric ratios. No absurd Answers or else you would get reported. It's better to answer o
    11·2 answers
  • Martin has 8 pints of soup in a pan.
    14·2 answers
  • What is x divided by 3 plus 2 divided by 5 equals one over fifteen
    15·1 answer
  • Graph -9x + 5y = 45<br><br>​
    5·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!