Ch 4 and 6 review

For a standard normal distribution, find the z-score that corresponds to the cumulative area 0.428.P(z  > c) = 0.428. Find c rounded to four decimal places.

• .1818

• .1815

• .1814

• .1800

Find the area of the shaded region under the standard normal distribution to the left of the given z-score. Round your answer to four decimal places.

P(z<2.29)=

• .011

• .998

• .012

• .989

A particular fruit's weights are normally distributed, with a mean of 265 grams and a standard deviation of 31 grams. If you pick one fruit at random, what is the probability that it will weigh between 274 grams and 348 grams

• .3821

• .298

• .389

• .2889

For a normal variable with mean 69.7 and  the standard deviation is 17.3  find the probability that a randomly selected value is at least 32.15

a) Choose the best choice that represents the probability statement.

For a normal variable with mean 69.7 and  the standard deviation is 17.3  find the probability that a randomly selected value is at least 32.15

Find the probability.

• .895

• .015

• .899

• .985

According to a study, 70 % of adult smokers started smoking before 21 years old. 8 smokers 21 years old or older are randomly selected, and the number of smokers who started smoking before 21 is recorded. Round to three decimal places. The probability that at most 4 of them started smoking before 21 years of age is

https://homepage.divms.uiowa.edu/~mbognar/applets/bin.html

• .914

• .414

• .194

• .149

According to a study, 70 % of adult smokers started smoking before 21 years old. 8 smokers 21 years old or older are randomly selected, and the number of smokers who started smoking before 21 is recorded. Round to three decimal places. The probability that exactly 3 of them started smoking before 21 years of age is

https://homepage.divms.uiowa.edu/~mbognar/applets/bin.html

• .047

• .953

• .074

• .084

The following talbe shows the number of dogs per household in Brownsville.

Find the missing value of th probability distribution, mean and standard deviation.

https://www.mathportal.org/calculators/statistics-calculator/probability-distributions-calculator.php

• .4, 2, 1

• .35, 1, 1.1

• .35, 2, 1

• .35, 1.8. 1.1

A high school baseball player has a 0.171 batting average. In one game, he gets 8 at bats. What is the probability he will get at least 2 hits in the game? Round to three decimal places.

https://homepage.divms.uiowa.edu/~mbognar/applets/bin.html

• .4

• .409

• .408

• .41

A manufacturing machine has a 3% defect rate.

If 10 items are chosen at random, what is the probability that at least one will have a defect?

Round to three decimal places

https://homepage.divms.uiowa.edu/~mbognar/applets/bin.html

• .263

• .3

• .26

• .262