An educational psychologist wishes to know the mean number of words a third grader can read per minute. she wants to make an estimate at the 90% level of confidence. for a sample of 837 third graders, the mean words per minute read was 24.9. assume a population standard deviation of 5.1. construct the confidence interval for the mean number of words a third grader can read per minute. round your answers to one decimal place.

(24.6 , 25.2)

Step-by-step explanation:

Formula to find the confidence interval for population mean () is given by :-

, where = Sample mean

z* = Critical z-value. (By z-table)

= Population standard deviation.

n= Sample size.

As per given , we have

n= 837

The critical value for 90% confidence interval : z* = 1.645 (By z-table)

The confidence interval for the mean number of words a third grader can read per minute will be :

∴  The confidence interval for the mean number of words a third grader can read per minute= (24.6 , 25.2)

step-by-step explanation:

. your answer will contain x - and y -terms. (1 point) x ( ¿¿ 2 − 7 ) 2 +( y 2 − 9 ) 2 √ ¿ 12. what is the distance from the directrix (the crocodile river) to the point ( x , y )? write this equation. your answer will contain a y -term.