The average per capita income for residents of Pennsylvania is $32,711 with a standard deviation of $3,100. If the variable is normally distributed, find the probability that the mean income of a sample of 50 residents would be less than $33,000. Express your answer as a decimal to four decimal places.

Find the length that separates premature babies from those who are not premature.

With the extra data value,  the range, standard deviation, and variance is?

On a nationwide math test, the mean was 58 and the standard deviation was 4. If Roberto scored 70, what was his z-score? Use the formula Z where is the mean, o is σ the standard deviation, and x is Roberto's score. Round to 4 decimal places. X н =

The weights of steers in a herd are distributed normally. The standard deviation is 200lbs and the mean steer weight is 1400lbs. Find the probability that the weight of a randomly selected steer is between 1539 and 1679lbs. Round your answer to four decimal places.

A researcher is using a chi-square test to determine whether there are any preferences among 4 brands of orange juice. With alpha = 0.05 and n = 30, the critical region for the hypothesis test would have a boundary of: Seleccione una: O A. 7.81 O B. 8.17 O C. 8.71 O D. 42.25

The lifespans of lizards in particular zoo are normally distributed. The average lizard lives 3.1 yearsthe standard deviation is 0.6 years. Find the probability that the lizards live longer than 3.1 years or less than 2.5 yearsHint: Draw and label a normal curve and use the percentages of the standard deviations. Write your answer using only numbers and do not include units. For example 95.3% would be entered as 95.3

You want to know the percentage of utility companies that earned revenue greater than 94 million dollars. If the mean revenue was 60 million dollars and the data has a standard deviation of 15 million, find the percentage. Assume that the distribution is normal. Round your answer to the nearest hundredth.

If you buy one ticket everyday for 365 days, find the mean and standard deviation for the numbers of winning tickets in such groups of 365 tickets. Round to three decimal places

A psychologist created a questionnaire to assess people's aggression. Assume that the questionnaire responses are regularly distributed with a standard deviation of 100. Assume that 15% of the scores are higher than 700. Determine the mean of the score distribution. Calculate your intermediate results to at least four decimal places. Round your answer to the nearest decimal point.