Help! Apparently I did these two problems wrong but I don't know what I did.

A toy manufacturer claims that the mean time that its top-selling toy captures children's attention is at least 45 minutes. Supp

riadik2000 [5.3K]

Answer:

$H_0:\mu =45\\\\H_a:\mu\geq 45$

Step-by-step explanation:

Since we have given that

A toy manufacturer claims that the mean time that its top-selling toy captures children's attention is at least 45 minutes.

Since we need to carry out a hypothesis test whether he can refute the claim.

We always take the alternate hypothesis such that it should satisfy the given statement.

And the null hypothesis can be equal to mean or other than that is given in alternate hypothesis.

So, hypothesis :

$H_0:\mu =45\\\\H_a:\mu\geq 45$

5 0

2 years ago

I don’t know this some one please help

Alexxx [7]

Answer:

A

Step-by-step explanation:

Antonia: 150 x 12 + 4,500 = 6,300

Cal: 250 x 12 + 3,400 = 6,400

5 0

2 years ago

30 random samples of high school students were asked if they played a sport for their high school. Each sample was 20 students.

Ludmilka [50]

Answer:

a. This option is correct

b. This will be true only if we take the mode as the best representative value

c. This is a correct choice

d. This is not a correct choice

Step-by-step explanation:

Statistics

We are given a dot plot representing 30 random sample proportions of high school students about their sports activities. Based on the data extracted from the plot, we can make some basic conclusions and, less accurately, some predictions.

From the data plot we can see that the following proportions were obtained, along with their absolute frequencies:

0.05 -> 3

0.10 -> 8

0.15 -> 7

0.20 -> 5

0.25 -> 4

0.30 -> 2

Let's select which of the following options are correct

a. A sample proportion of 0.20 means that 4 of 20 high school students responded that they play a sport.

The ratio between the sport playing students to the total of high school students is

$\displaystyle \frac{4}{20}=\frac{1}{5}=0.20$

Thus, this statement is correct.

b. The best prediction for the proportion of all high school students that play a sport is 0.10.

This will be true only if we take the mode as the best representative value for the whole dataset. Personally, I don't like to trust the mode as a good central tendency result, I'd prefer the mean instead.

c. The mean of the 30 sample proportions calculated to the nearest hundredth is 0.16

Computing the mean of the sample proportions

$\displaystyle \bar x=\frac{\sum x_i.f_i}{\sum f_i}$

$\displaystyle \bar x=\frac{0.00\cdot 1+0.05\cdot 3+0.10\cdot 8+0.15\cdot 7+0.20\cdot 5+0.25\cdot 4+0.30\cdot 2}{1+3+8+7+5+4+2}$

$\bar x\approx 0.16$

This is a correct choice

d. The shape of the sample distribution is fairly symmetrical

We can see the distribution if left-skewed because its peak value is not at the mean value. The mode and the mean are fairly different, thus this choice is not correct

5 0

2 years ago

Read 2 more answers

Analyzing a Graphical Relationship

Step2247 [10]

Answer: A : decreasing B : constant C: increasing D: Constant

Step-by-step explanation:

6 0

3 years ago

Write the equation of a line in slope intercept form that is perpendicular to the line y = –4x and passes through the point (2,

Gnesinka [82]

1. If the line that we are searching for is perpendicular to the line y = -4x, this means that the gradient of our line and the gradient of the perpendicular line will multiply to give -1. Thus if we call the gradient of our line m, then:

m*(-4) = -1

-4m = -1

m = 1/4

2. Since we know that m = 1/4 and we have a point (2,6) on our line, we can use the formula y - y1 = m(x - x1) to find the equation of our line, where (x1, y1) is the coordinates of a point on the line. Thus:

y - y1 = m(x - x1)

y - 6 = (1/4)(x - 2)

y - 6 = (1/4)x - 2/4 (Expand (1/4)(x - 2))

y = (1/4)x - 1/2 + 6 (Simplify 2/4 and add 6 to each side)

y = (1/4)x + 11/2 (Evaluate -1/2 + 6)

Slope-intercept form is given by y = mx + c. As our equation is already in this form, there is nothing more to do. Thus, the answer is y = (1/4)x + 11/2

6 0

2 years ago