Evaluate each expression for d = -3.

A market researcher for a provider of music player accessories wants to know the proportion of customers who own cars to assess

AVprozaik [17]

Answer:

a) The estimated standard deviation of the sampling distribution of the proportion is 0.023

b) the estimated standard deviation have been if he had surveyed only 100 customers is 0.046

Step-by-step explanation:

given information:

the number of sample, n = 400

sample proportion, p = 70% = 0.7

a) standard deviation of a sample proportion is

σ = $\sqrt{\frac{p(1-p)}{n}}$

= $\sqrt{\frac{0.7 (1-0.7)}{400} }$

= 0.023

b) if n = 100, so

σ = $\sqrt{\frac{p(1-p)}{n}}$

= $\sqrt{\frac{0.7 (1-0.7)}{100} }$

= 0.046

7 0

3 years ago

You have a coupon for $5 off an oil change. When you arrive at the auto repair

Anestetic [448]

The function that represents how much you would pay is:

p(x) = (x - $5)*0.9

<h3>How to find the function?</h3>

Let's say that the cost of the repair is x.

First, we apply the coupon, so we discount $5 for the cost.

x - $5.

Then we apply another discount of the 10%, this is written as:

(x - $5)*(1 - 10%/100%)

(x - $5)*(1 - 0.1)

(x - $5)*0.9

Then the function that represents how much you would pay is:

p(x) = (x - $5)*0.9

If you want to learn more about functions:

brainly.com/question/4025726

#SPJ1

6 0

2 years ago

10 coupons are given to 20 shoppers in a store. Each shopper can receive at most one coupon. 5 of the shoppers are women and 15

zmey [24]

Answer:

$\, {20 \choose 10} - {15 \choose 10}$

Step-by-step explanation:

We can find the total amount of ways at least a woman receives a coupon by calculating the total amount of possibilities ot distribute the coupon and substract it to the total amount of possibilities to distribute 10 coupons to the 15 men (this is the complementary case that at least a woman receives a cupon).

- The total amount of possibilities to distribute the coupons among the 20 shoppers is equivalent to the total amount of ways to pick a subset of 10 elements from a set of 20. This is the combinatiorial number of 20 with 10, in other words, $\, {20 \choose 10} = \frac{20!}{10!10!} .$

- To calculate the total amount of possibilities to distribute the coupons among the 15 men, we need to make the same computation we made above but with a set of 15 elements instead of 20. This gives us $\, {15 \choose 10} = \frac{15!}{10!5!}$ possibilities.