What volume of a 0.1 M NaOH solution must be combined with 25 mL of 0.2 M HNO3 to reach a pH of 11.5?

Consider the following reaction. 2 A + B −→ P A table of initial rates with initial concentrations of A and B is given below. [A]o (M) [B]o (M) rate M s 0.2 0.1 1.2 × 10−5 0.4 0.1 2.4 × 10−5 0.4 0.2 9.2 × 10−5 0.1 0.1 6.0 × 10−6 What is the rate expression? (a) r = k[A] [B]2 (b) r = k[A] [B] (c) r = k[A]2 [B] (d) r = k[A]2 [B]2

A stock's returns have the following distribution:

Assume the risk-free rate is 2%. Calculate the stock's expected return, standard deviation, coefficient of variation, and Sharpe ratio. Do not round intermediate calculations. Round your answers to two decimal places.

Stock's expected return:   %

Standard deviation:   %

Coefficient of variation:

Sharpe ratio:

Expected Return: Discrete Distribution

A stock's return has the following distribution:

Calculate the stock's expected return. Round your answer to two decimal places.
10.3 %

Calculate the standard deviation. Round your answer to two decimal places.

???? %

I was able to answer the first question but not the second. Could you help please?

I need to verify my answers are correct.

A large operator of timeshare complexes requires anyone interested in making a purchase to first visit the site of interest. Historical data indicates that 55% of all potential purchasers select a day visit, 25% choose a one-night visit, and 20% opt for a two-night visit. In addition, 10% of day visitors ultimately make a purchase, 25% of night visitors make a purchase, and 20% of those visiting for two nights make a purchase. Suppose a visitor is randomly selected

(a) What is the probability that the visitor makes a purchase?

(my answer was 0.1 * 0.55 + 0.25 * 0.25 + 0.2 * 0.2 = 0.1575)

(b) What is the probability that the visitor visited for two nights given that they made a purchase.

(my answer was found using bayes theorem: (0.25 * 0.2)/0.1575 = 0.31746

(c) What is the probability that the visitor visited for one night given that they did not make a purchase?

(my answer was: (1 - 0.25)(0.25)/(1 - 0.1575) = 0.22255

Thanks for your help

1. Amy tosses 12 biased coins. Each coin comes up heads with probability 0.2. What is the probability that fewer than 3 of the coins come up heads?

Answer: 0.5583

2. Amy shoots 27000 arrows at a target. Each arrow hits the target (independently) with probability 0.2. What is the probability that at most 2 of the first 15 arrows hit the target?

Answer: 0.398

3. Amy tosses 19 biased coins. Each coin comes up heads with probability 0.1. What is the probability that more than 1 of the coins come up heads?

Answer: 0.5797

4. Amy shoots 49000 arrows at a target. Each arrow hits the target (independently) with probability 0.2. What is the probability that fewer than 3 of the first 12 arrows hit the target?

Answer: 0.5583

5. Amy rolls 16 8-sided dice. What is the probability that fewer than 1 of the rolls are 1s?

Answer: 0.1181

the number of fire engines available to extinguish fires in a small town is two. When a fire occurs it occupies one fire engine for a full day. If the occurence of fires is Poisson distributed with a mean of 0.7 per day, what is the probability that a fire will occur for which no engine is available?

Suppose that a financial analyst collected the following data: rate of return on T-bill is 2.5%

Market risk premium is = 5%; company's beta is 0.7; D₁ = $2.00; current stock price is

$30.00; future growth of dividends is 6%.

What estimate should the analyst use?

A manufacturer knows that their items have a normally distributed lifespan, with a mean of 2.7 years, and standard deviation of 0.7 years.

If 6 items are picked at random, 4% of the time their mean life will be less than how many years?

Give your answer to one decimal place.

Assume the random variable X has a binomial distribution with the given probability of obtaining a success. Find the following probability, given the number of trials and the probability of obtaining a success. Round your answer to four decimal places.

P(X=14), n=15, p=0.7