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
nordsb [41]
3 years ago
13

A student takes a multiple choice test with 40 questions. The probability that a student answers a given question correctly is 0

.5, independent of all other questions. The probability that the student answers more than N questions correctly is greater than 0.10. The probability that the student answers more than N+1 questions correctly is less than 0.10. Calculate N using normal approximation with continuity correction. Answer is 23. Please explain your work.
Mathematics
1 answer:
LenKa [72]3 years ago
6 0

Answer:

Step-by-step explanation:

X no of questions student answers is binomial with n =40 and p =0.5

If approximated to normal, X is Normal with

mean = np = 20 and variance = npq = 10

P(X>N) >0.10

We use std normal distribution table to get z value first then convert to x value

z>-1.28

So x>20-1.28(10) = 20-12.8 = 7.2

This is with continuity correction.

Hence without continuity correction this equals 7.2-0.5 = 6.7

x>6.7

n = 7

You might be interested in
Find the unknown 8/28 = m/7
vredina [299]
The answer to the question is m = 2
6 0
3 years ago
Read 2 more answers
The price of products may increase due to inflation and decrease due to depreciation. Marco is studying the change in the price
likoan [24]

Answer:

A)  3%

B)  Product A

Step-by-step explanation:

<u>Exponential Function</u>

General form of an exponential function: y=ab^x

where:

  • a is the initial value (y-intercept)
  • b is the base (growth/decay factor) in decimal form
  • x is the independent variable
  • y is the dependent variable

If b > 1 then it is an increasing function

If 0 < b < 1 then it is a decreasing function

<u>Part A</u>

<u>Product A</u>

Assuming the function for Product A is <u>exponential</u>:

f(x) = 0.69(1.03)^x

The base (b) is 1.03.  As b > 1 then it is an <u>increasing function</u>.

To calculate the percentage increase/decrease, subtract 1 from the base:

⇒ 1.03 - 1 = 0.03 = 3%

Therefore, <u>product A is increasing by 3% each year.</u>

<u>Part B</u>

\sf percentage\:change=\dfrac{final\:value-initial\:value}{initial\:value} \times 100

To calculate the percentage change in Product B, use the percentage change formula with two consecutive values of f(t) from the given table:

\implies \sf percentage\:change=\dfrac{10201-10100}{10100}\times 100=1\%

Check using different two consecutive values of f(t):

\implies \sf percentage\:change=\dfrac{10303.01-10201}{10201}\times 100=1\%

Therefore, as 3% > 1%, <u>Product A recorded a greater percentage change</u> in price over the previous year.

Although the question has not asked, we can use the given information to easily create an exponential function for Product B.

Given:

  • a = 10,100
  • b = 1.01
  • n = t - 1 (as the initial value is for t = 1 not t = 0)

\implies f(t) = 10100(1.01)^{t-1}

To check this, substitute the values of t for 1 through 4 into the found function:

\implies f(1) = 10100(1.01)^{1-1}=10100

\implies f(2) = 10100(1.01)^{2-1}=10201

\implies f(3) = 10100(1.01)^{3-1}=10303.01

\implies f(4) = 10100(1.01)^{4-1}=10406.04

As these values match the values in the given table, this confirms that the found function for Product B is correct and that <u>Product B increases by 1% per year.</u>

4 0
2 years ago
Need help finding the parallel and perpendicular slope
Rudik [331]

Answer:

Step-by-step explanation:

(x₁, y₁) = (19 , -4)   & (x₂ ,y₂) = (17, -20)

Slope =\frac{y_{2}-y_{1}}{x_{2}-x_{1}}

        = \frac{-20-[-4]}{17-19}\\\\= \frac{-20+4}{17-19}\\\\= \frac{-16}{-2}\\\\= 8

m = 8

Parallel lines have same slope.

Parallel slope = 8

Slope of perpendicular line = \frac{-1}{m}

Perpendicular slope = \frac{-1}{8}

8 0
3 years ago
Hey I’m struggling with number 13 so please show your work. Thx
Dafna11 [192]

Answer:

\frac{5}{12}

Step-by-step explanation:

Because \frac{3}{5} is being multiplied by S, we can divide \frac{3}{5} from both sides of the equation. This will give us:

\frac{1}{4}÷\frac{3}{5}

But, that looks a bit hectic. Instead of dividing, you can multiply by the reciprocal (which is essentially how to divide fractions). So, instead of \frac{1}{4}÷\frac{3}{5}, you get:

\frac{1}{4}×\frac{5}{3}

When multiplying fractions, remember you can just multiply straight across-- numerator x numerator, then denominator x denominator.

By doing that, you get the fraction \frac{5}{12}

\frac{5}{12} cannot be simplified any more, so S=\frac{5}{12} is your answer :)

I hope this helps

6 0
3 years ago
Kira has $40 to spend and used $20 to buy a new pair of jeans. Which integer best represents the situation of spending $20?
pishuonlain [190]
-20 because 40 is a positive and spent is negative
5 0
3 years ago
Other questions:
  • What is the most efficient first step to isolate the variable term on one side of this equation?
    9·1 answer
  • How much longer do the turkey need to cook
    5·2 answers
  • If (8z − 9)(8z + 9) = az2 − b, what is the value of a? (5 points)
    5·1 answer
  • Find the distance from P to l. Line l contains points (-4,2) and (3,-5).Point P has coordinates (1,2).
    10·1 answer
  • Find the value of the following expression
    14·1 answer
  • Which graph represents −9x+4y≤8 (Choice A) (Choice B) (Choice C) (Choice D) <br> khan academy
    12·1 answer
  • Are the triangles below acute, obtuse or right?
    15·2 answers
  • What is the percent of change from 800,000 to 1,000,000?
    5·1 answer
  • Rewrite the sum of 96 + 80 using the distrubutive property
    10·2 answers
  • 10. The following frequency table contains the total number of deaths worldwide as a result of earthquakes from 2000 to 2012.Yea
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!