# Pre-Calculus

The table below shows a frequency distribution of the number of pickup trucks sold at 85 truck dealerships in Maine over an 18-month period.

Number of trucks sold/Number of dealerships:

70-90/2
90-110/11
110-130/39
130-150/17
150-170/9
170-190/7

Find the interval about the sample mean such that the probability is 0.90 that the true mean lies within the interval. (When P=90%, t=1.65)

I know that N=85, but I do not know how to find the standard deviation or mean in order to work the rest of the problem. Any help would be great.

1. 👍 0
2. 👎 0
3. 👁 45
1. Frankly, I would assign numbers to do the mean, standard deviation.
Change your frequency to actual data
80,80, 100,100,100,100,100,100, (eleven 100's), 120 (39 of these). Your calculator can be your best friend doing this.

1. 👍 0
2. 👎 0

## Similar Questions

1. ### Pre-Calculus

The table below shows a frequency distribution of the number of pickup trucks sold at 85 truck dealerships in Maine over an 18-month period. Number of trucks sold/Number of dealerships: 70-90/2 90-110/11 110-130/39 130-150/17

asked by Mary on October 26, 2008
2. ### Algebra 2

"At a school sponsored car wash, the fees charged were: \$5 per car, \$8 per truck, \$10 per van. Twice as many cars were washed as pickup trucks. The amount collected for washing cars and pickup trucks was \$360. A total of \$410 was

asked by Anonymous on March 26, 2009
3. ### math

In one month a salesman sold a total of 30 cars and trucks. If three times the number of cars sold equals twice the number of trucks sold, how many trucks did he sell?

asked by jane on April 18, 2016
4. ### math

the study of finances of Glassford motors has shown that the profit of the company is modeled by p=-2n^2+800n+370000, where p is profit in dollars, and n is the number of trucks sold a) at what point (how many trucks sold) will

asked by jolyne on June 23, 2019
5. ### math

The Following Table gives the sales for the Sasquatch Men's Shoe store: Shoe Size , Frequency (number of pairs sold) 4 , 8 5 , 12 6 , 31 7 , 50 8 , 58 9 , 46 10 , 37 11 , 14 12 , 11 1)determine the mean for the distribution,

asked by josh on December 3, 2016
6. ### Physics

2. Two pickup trucks crash at a 90 degree intersection. If the momentum of pickup A is 4.60 x10^4 kg km/h north and the momentum of pickup B is 6.25 x 10^4 kg km/h east, what is the magnitude of the resulting momentum of the final

asked by Sotha Bun on March 18, 2017
7. ### Math...LOST!!

Heights The frequency distribution indicates the heights of 45 male high school seniors. Height(in.) Number of Males 64 2 65 6 66 7 67 9 68 10 69 6 70 3 71 0 72 2 a) Construct a histogram of the frequency distribution. b)

asked by Jen on July 31, 2011
8. ### physics

number of pickup trucks and the number of points.What goes on the x axis

asked by Anonymous on October 5, 2011
9. ### math

1. To form a __________ we form a ratio between each frequency and the total number of scores in the set. (Points: 5) stem-and-leaf display frequency distribution relative frequency distribution frequency polygon

asked by Anonymous on November 7, 2011
10. ### MATH

The frequency distribution indicates the heights of 45 male high school seniors. Height(in.) Number of Males 64 2 65 6 66 7 67 9 68 10 69 6 70 3 71 0 72 2 a) Construct a histogram of the frequency distribution. b) Construct a

asked by Jen on August 1, 2011

More Similar Questions