mary’s father bought a chair. The list price was $50, but he received a 30% discount. How much did the chair cost?

vagabundo [1.1K]

If two shapes are 'similar', it means that the dimensions of the shapes have the same ratio towards each other. In this example, we can see that the side with a length of 2 correlates to the side with a length of 4. That means, the scaling ratio is 4:2, which can be reduced to 2:1.

The next step is to look at the other side. We know that the width of the smaller shape is 1, and that the second shape is twice the size of the smaller shape (which is what a scale of 2:1 means). Therefore, you just need to multiply the known width by two to get the unknown.

1 * 2 = 2

The missing side _d_ has a length of 2.
Hope that helped =)

8 0

3 years ago

What is 9 superscript 7 written in expanded form? 9 + 9 + 9 + 9 + 9 + 9 + 9 9 times 9 times 9 times 9 times 9 times 9 times 9 7

GrogVix [38]

Answer:

4,782,969

Step-by-step explanation:

9^7

Written in expanded form = 9 times 9 times 9 times 9 times 9 times 9 times 9

= 9 × 9 × 9 × 9 × 9 × 9 × 9

= 4,782,969

9^7 means multiplying 9 in 7 places

9^7 = 4,782,969

3 0

2 years ago

Read 2 more answers

The table below shows the outputs y for different inputs x:

igor_vitrenko [27]

Part A)
The table doesn't represent y as a function of x.
Why? One reason is that 1 or 3 is the first element in more than one ordered pair.
Part B)
f(x) = 10x + 20
f(120)= 10*120 + 20 = 1200 + 20 = 1220
f(120) represents cost of boating for 120 hours.

3 0

3 years ago

Read 2 more answers

Find the volume of a right circular cone that has a height of 17.8 ft and a base with a radius of 17.8 ft. Round your answer to

Alona [7]

Answer:

5905.9 ft

Step-by-step explanation:

5 0

3 years ago

In college basketball, a shot made from beyond a designated arc radiating about 20 ft from the basket is worth three points ins

denis-greek [22]

Answer:

a) By the Central Limit Theorem, the distribution would be approximately normal, with mean $\mu = 0.45$ and standard deviation $s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.45*0.55}{100}} = 0.0497$

b) 4.02 standard deviations below the mean.

c) Making 25 or less shots has a pvalue of -4.02. Z-scores lower than -2 are considered surprising, so yes, it would be surprising for him to make only 25 of these shots.

Step-by-step explanation:

To solve this question, we are going to need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For proportions, we have that the mean is $\mu = p$ and the standard deviation is $s = \sqrt{\frac{p(1-p)}{n}}$

In this problem, we have that:

$p = 0.45, n = 100$

a)By the Central Limit Theorem, the distribution would be approximately normal, with mean $\mu = 0.45$ and standard deviation $s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.45*0.55}{100}} = 0.0497$

b)This is Z when X = 0.25.

$Z = \frac{X - \mu}{\sigma}$

By the Central Limit Theorem

$Z = \frac{X - \mu}{s}$

$Z = \frac{0.25 – 0.45}{0.0497}$

$Z = -4.02$

4.02 standard deviations below the mean.

c) Making 25 or less shots has a pvalue of -4.02. Z-scores lower than -2 are considered

surprising, so yes, it would be surprising for him to make only 25 of these shots.

3 0

3 years ago