normally distributed with an unknown population mean and a population standard deviation of 4.5 points. A random sample of 45 scores is taken and gives a sample mean of 84. Find a 90% confidence interval

= ( 82.90, 85.10) points

Therefore at 90% confidence interval (a,b)= ( 82.90, 85.10) points

Step-by-step explanation:

Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.

The confidence interval of a statistical data can be written as.

x+/-zr/√n

Given that;

Mean x = 84

Standard deviation r = 4.5

Number of samples n = 45

Confidence interval = 90%

z(at 90% confidence) = 1.645

Substituting the values we have;

84+/-1.645(4.5/√45)

84+/-1.645(0.670820393249)

84+/-1.10

= ( 82.90, 85.10) points

Therefore at 90% confidence interval (a,b)= ( 82.90, 85.10) points

answer: the answer is (b) amie should have multiplied

step-by-step explanation: given a sphere and a cylinder with same radius and height.

let, 'r' be the radius of the cylinder and sphere and 'h' be the height of the cylinder. according to the question,

r = h.

now, the volume of the sphere will be

and the volume of the cylinder will be

therefore, we have

thus, ammie should have multiplied the volume of the sphere

answer: all of the odd numbers were opened

the first person was the one that was opening all of the lockers. since one is odd, this causes all of the odd number lockers to be opened in the end.