Please help, I'm confused.

An accelerated life test on a large number of type-D alkaline batteries revealed that the mean life for a particular use before

joja [24]

Answer:

option (d) 16.6 and 21.4

Step-by-step explanation:

Data provided in the question:

The mean life for a particular use before they failed = 19.0 hours

The distribution of the lives approximated a normal distribution

The standard deviation of the distribution = 1.2 hours

To find:

The values between which 95.44 percent of the batteries failed

Now,

In Normal distribution, the approximately 95% ( ≈ 95.44% of all values ) falls within 2 standard deviations of the mean

Therefore,

Upper limit = Mean + 2 × standard deviation

⇒ Upper limit = 19.0 + 2 × 1.2 = 21.4

Lower limit = Mean - 2 × standard deviation

⇒ Lower limit = 19 - 2 × 1.2 = 16.6

Hence,

the answer is option (d) 16.6 and 21.4

8 0

3 years ago

Evaluate the expression when c=21 and d=4. c-5d

vekshin1

$\huge \boxed{\mathfrak{Question} \downarrow}$

Evaluate the expression when c = 21 and d = 4, c - 5d = ?

$\large \boxed{\mathfrak{Answer \: with \: Explanation} \downarrow}$

Given,

c = 21
d = 4
c - 5d = ?

Let's solve it now :-

$\sf \: c - 5d \\ \\ \sf \: Substitute \: the \: values \: of \: c \: and \: d \\ \\ \sf c - 5d \\ \rightarrow \sf(21) - 5(4) \\ \sf \rightarrow21 - 20 \\ = \boxed{\boxed{\bf \: 1}}$

The value of the expression is 1.

6 0

3 years ago

What is the problem that give you the answer x^2 + 8x + 15

kirza4 [7]

23 is the best answer for this question

7 0

4 years ago

Read 2 more answers

Joel looks at a map of Colorado, scowls, and tears it to shreds. "I don't need this lousy map," he mutters, puffing out his ches

Andru [333]

Answer:12 x 9

Step-by-step explanation: 600 x 2/100 = 1200/100 = 12

450 x 2/100 = 900/100 = 9

Remember that 100km = 2 units

5 0

3 years ago

Read 2 more answers

How many extraneous solutions does the equation below have? StartFraction 9 Over n squared 1 EndFraction = StartFraction n 3 Ove

BigorU [14]

The equation has one extraneous solution which is n ≈ 2.38450287.

Given that,

The equation;

$\dfrac{9}{n^2+1} =\dfrac{n+3}{4}$

We have to find,

How many extraneous solutions does the equation?

According to the question,

An extraneous solution is a solution value of the variable in the equations, that is found by solving the given equation algebraically but it is not a solution of the given equation.

To solve the equation cross multiplication process is applied following all the steps given below.

$\rm \dfrac{9}{n^2+1} =\dfrac{n+3}{4}\\\\9 (4) = (n+3) (n^2+1)\\\\36 = n(n^2+1) + 3 (n^2+1)\\\\36 = n^3+ n + 3n^2+3\\\\n^3+ n + 3n^2+3 - 36=0\\\\n^3+ 3n^2+n -33=0\\$

The roots (zeros) are the x values where the graph intersects the x-axis. To find the roots (zeros), replace y

with 0 and solve for x. The graph of the equation is attached.

n ≈ 2.38450287

Hence, The equation has one extraneous solution which is n ≈ 2.38450287

For more information refer to the link.

brainly.com/question/15070282

5 0

3 years ago