A. A man weighs 185 lb. What is his mass in grams?

Georgianna claims that in a small city renowned for its music school, the average child takes at least 5 years of piano lessons.

Allisa [31]

Answer:

The condition are

The Null hypothesis is $H_o : \mu = 5$

The Alternative hypothesis is $H_a : \mu < 5$

The check revealed that

There is sufficient evidence to support the claim that in a small city renowned for its music school, the average child takes at least 5 years of piano lessons

Step-by-step explanation:

From the question we are told that

The population mean is $\mu = 5 \ year$

The sample size is n = 20

The sample mean is $\= x = 4.6 \ years$

The standard deviation is $\sigma = 2.2 \ years$

The Null hypothesis is $H_o : \mu = 5$

The Alternative hypothesis is $H_a : \mu < 5$

So i will be making use of $\alpha = 0.05$ level of significance to test this claim

The critical value of $\alpha$ from the normal distribution table is $Z_\alpha = 1.645$

Generally the test statistics is mathematically evaluated as

$t = \frac{\= x - \mu}{ \frac{\sigma }{\sqrt{n} } }$

substituting values

$t = \frac{ 4.6 - 5}{ \frac{2.2}{\sqrt{20} } }$

$t = -0.8131$

Looking at the value of t and $Z_{\alpha }$ we see that $t < Z_{\alpha }$ so we fail to reject the null hypothesis

This implies that there is sufficient evidence to support the claim that in a small city renowned for its music school, the average child takes at least 5 years of piano lessons.

4 0

3 years ago

An angelfish was 1 1/2 inches long when it was bought. Now it is 2 1/3 inches long.

____ [38]

A)

Earlier, The length of the angelfish = $1 \frac{1}{2}$ inches

Now, the length of angelfish = $2 \frac{1}{3}$ inches

We have to determine the grown length of angelfish

= $2 \frac{1}{3}$ - $1 \frac{1}{2}$

= $\frac{7}{3}- \frac{3}{2}$

LCM of '2' and '3' is '6',

= $\frac{14-9}{6}$

= $\frac{5}{6}$ inch

Therefore, the angelfish has grown by $\frac{5}{6}$ inch.

B)

We have to determine the increased length of angelfish in feet.

Since $1 inch = \frac{1}{12}$ foot

So, $\frac{5}{6} inch = \frac{5}{6} \times \frac{1}{12} = \frac{5}{72}$

= 0.069 foot.

7 0

3 years ago

Read 2 more answers

Which is a real-world example of two planes intersecting?

leva [86]

The answer to the question above is the third choice, "a shelf on a wall". The shelf is usually made of rectangular pieces of materials that are then connected to each other to form quadrilaterals. The sides of the shelf are planes.

8 0

3 years ago

Read 2 more answers

Find two power series solutions of the given differential equation about the ordinary point x = 0. compare the series solutions

monitta

I don't know what method is referred to in "section 4.3", but I'll suppose it's reduction of order and use that to find the exact solution. Take $z=y'$ , so that $z'=y''$ and we're left with the ODE linear in $z$ :

$y''-y'=0\implies z'-z=0\implies z=C_1e^x\implies y=C_1e^x+C_2$

Now suppose $y$ has a power series expansion

$y=\displaystyle\sum_{n\ge0}a_nx^n$
$\implies y'=\displaystyle\sum_{n\ge1}na_nx^{n-1}$
$\implies y''=\displaystyle\sum_{n\ge2}n(n-1)a_nx^{n-2}$

Then the ODE can be written as

$\displaystyle\sum_{n\ge2}n(n-1)a_nx^{n-2}-\sum_{n\ge1}na_nx^{n-1}=0$

$\displaystyle\sum_{n\ge2}n(n-1)a_nx^{n-2}-\sum_{n\ge2}(n-1)a_{n-1}x^{n-2}=0$

$\displaystyle\sum_{n\ge2}\bigg[n(n-1)a_n-(n-1)a_{n-1}\bigg]x^{n-2}=0$

All the coefficients of the series vanish, and setting $x=0$ in the power series forms for $y$ and $y'$ tell us that $y(0)=a_0$ and $y'(0)=a_1$ , so we get the recurrence

$\begin{cases}a_0=a_0\\\\a_1=a_1\\\\a_n=\dfrac{a_{n-1}}n&\text{for }n\ge2\end{cases}$

We can solve explicitly for $a_n$ quite easily:

$a_n=\dfrac{a_{n-1}}n\implies a_{n-1}=\dfrac{a_{n-2}}{n-1}\implies a_n=\dfrac{a_{n-2}}{n(n-1)}$

and so on. Continuing in this way we end up with

$a_n=\dfrac{a_1}{n!}$

so that the solution to the ODE is

$y(x)=\displaystyle\sum_{n\ge0}\dfrac{a_1}{n!}x^n=a_1+a_1x+\dfrac{a_1}2x^2+\cdots=a_1e^x$

We also require the solution to satisfy $y(0)=a_0$ , which we can do easily by adding and subtracting a constant as needed:

$y(x)=a_0-a_1+a_1+\displaystyle\sum_{n\ge1}\dfrac{a_1}{n!}x^n=\underbrace{a_0-a_1}_{C_2}+\underbrace{a_1}_{C_1}\displaystyle\sum_{n\ge0}\frac{x^n}{n!}$

4 0

3 years ago

What binomial is a factor of the trinomial x^2-5x+4

Svetradugi [14.3K]

Explanation:

Let the equation be

a

⋅

x

2

+

b

⋅

x

+

c

. To factorize multiplication of a and c i.e. ac so that sum of factors, if ac is positive (and difference if ac is negative) is equal to b. Now split b into these two components and factorization will be easy.

4 0

4 years ago